trifluoperazine (Rx)

Schizophrenia

Outpatient

• 1-2 mg PO q12hr

Inpatient

• Initial: 2-5 mg PO q12hr
• Maintenance Dose: 15-20 mg/day
• Not to exceed 40mg/day

Non Psychotic Anxiety

1-2 mg PO q12hr

Maximum Dose: 6 mg/day; not to exceed 12 weeks

Renal Impairment

Dose adjustment not necessary following dialysis

Schizophrenia/Psychosis

Inpatient

• <6 years: Safety and efficacy not established
• 6-12 years old: 1 mg PO qDay or q12hr; not to exceed 15 mg/day
• 12 years old: 2-5 mg PO q12hr

Initiate dosing at the low end of the range; titrate gradually

Schizophrenia

Outpatient

- 1-2 mg PO q12hr

Inpatient

- Initial: 2-5 mg PO q12hr

- Maintenance Dose: 15-20 mg/day

- Not to exceed 40mg/day

Non Psychotic Anxiety

1-2 mg PO q12hr

Maximum Dose: 6 mg/day; not to exceed 12 weeks

Contraindicated (10)

• amisulpride

  amisulpride, trifluoperazine. Either increases toxicity of the other by Other (see comment). Contraindicated. Comment: Increases risk of neuroleptic malignant syndrome.

• disopyramide

  trifluoperazine and disopyramide both increase QTc interval. Contraindicated.

• ibutilide

  trifluoperazine and ibutilide both increase QTc interval. Contraindicated.

• indapamide

  trifluoperazine and indapamide both increase QTc interval. Contraindicated.

• metrizamide

  trifluoperazine, metrizamide. Mechanism: unknown. Contraindicated. Risk of seizure. D/C phenothiazine 24h before admin. of metrizamide.

• pentamidine

  trifluoperazine and pentamidine both increase QTc interval. Contraindicated.

• pimozide

  trifluoperazine and pimozide both increase QTc interval. Contraindicated.

• procainamide

  trifluoperazine and procainamide both increase QTc interval. Contraindicated.

• quinidine

  trifluoperazine and quinidine both increase QTc interval. Contraindicated.

• sotalol

  trifluoperazine and sotalol both increase QTc interval. Contraindicated.

Serious - Use Alternative (77)

• abametapir

  abametapir will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.

• aminolevulinic acid oral

  aminolevulinic acid oral, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid administering other phototoxic drugs with aminolevulinic acid oral for 24 hr during perioperative period.

• aminolevulinic acid topical

  trifluoperazine increases toxicity of aminolevulinic acid topical by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of photosensitizing drugs may enhance the phototoxic reaction to photodynamic therapy with aminolevulinic acid.

• amiodarone

  trifluoperazine and amiodarone both increase QTc interval. Avoid or Use Alternate Drug.

• amitriptyline

  trifluoperazine and amitriptyline both increase QTc interval. Avoid or Use Alternate Drug.

• amoxapine

  trifluoperazine and amoxapine both increase QTc interval. Avoid or Use Alternate Drug.

• apomorphine

  trifluoperazine decreases effects of apomorphine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• arsenic trioxide

  trifluoperazine and arsenic trioxide both increase QTc interval. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  trifluoperazine and artemether/lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• benzhydrocodone/acetaminophen

  benzhydrocodone/acetaminophen, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• bromocriptine

  trifluoperazine decreases effects of bromocriptine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• cabergoline

  trifluoperazine decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.

• calcium/magnesium/potassium/sodium oxybates

  trifluoperazine, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• chlorpromazine

  chlorpromazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• clarithromycin

  trifluoperazine and clarithromycin both increase QTc interval. Avoid or Use Alternate Drug.

• clomipramine

  trifluoperazine and clomipramine both increase QTc interval. Avoid or Use Alternate Drug.

• degarelix

  degarelix and trifluoperazine both decrease QTc interval. Avoid or Use Alternate Drug.

• desipramine

  trifluoperazine and desipramine both increase QTc interval. Avoid or Use Alternate Drug.

• dofetilide

  trifluoperazine and dofetilide both increase QTc interval. Avoid or Use Alternate Drug.

• dopamine

  trifluoperazine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.

• dosulepin

  trifluoperazine and dosulepin both increase QTc interval. Avoid or Use Alternate Drug.

• doxepin

  trifluoperazine and doxepin both increase QTc interval. Avoid or Use Alternate Drug.

• dronedarone

  trifluoperazine and dronedarone both increase QTc interval. Avoid or Use Alternate Drug.

• droperidol

  trifluoperazine and droperidol both increase QTc interval. Avoid or Use Alternate Drug.

• epinephrine

  epinephrine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• epinephrine racemic

  epinephrine racemic and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin base

  trifluoperazine and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  trifluoperazine and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  trifluoperazine and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin stearate

  trifluoperazine and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.

• fentanyl

  fentanyl, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl intranasal

  fentanyl intranasal, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transdermal

  fentanyl transdermal, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transmucosal

  fentanyl transmucosal, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fluconazole

  trifluoperazine and fluconazole both increase QTc interval. Avoid or Use Alternate Drug.

• fluphenazine

  fluphenazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• formoterol

  trifluoperazine and formoterol both increase QTc interval. Avoid or Use Alternate Drug.

• givosiran

  givosiran will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.

• haloperidol

  trifluoperazine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.

• hydrocodone

  hydrocodone, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• imipramine

  trifluoperazine and imipramine both increase QTc interval. Avoid or Use Alternate Drug.

• itraconazole

  trifluoperazine and itraconazole both increase QTc interval. Avoid or Use Alternate Drug.

• ketoconazole

  trifluoperazine and ketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• levodopa

  trifluoperazine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• levodopa inhaled

  trifluoperazine decreases effects of levodopa inhaled by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Phenothiazine/1st generation antipsychotics inhibit dopamine D2 receptors in varying degrees.

• levoketoconazole

  trifluoperazine and levoketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• lisuride

  trifluoperazine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.

• lofepramine

  trifluoperazine and lofepramine both increase QTc interval. Avoid or Use Alternate Drug.

• lumefantrine

  trifluoperazine and lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• maprotiline

  trifluoperazine and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.

• methyl aminolevulinate

  trifluoperazine, methyl aminolevulinate. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Each drug may increase the photosensitizing effect of the other.

• methyldopa

  trifluoperazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.

• metoclopramide intranasal

  trifluoperazine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
  
  trifluoperazine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for additive effects, including increased frequency and severity of tardive dyskinesia, other extrapyramidal symptoms, and neuroleptic malignant syndrome.

• moxifloxacin

  trifluoperazine and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• nilotinib

  trifluoperazine and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.

• nortriptyline

  trifluoperazine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.

• octreotide

  trifluoperazine and octreotide both increase QTc interval. Avoid or Use Alternate Drug.

• octreotide (Antidote)

  trifluoperazine and octreotide (Antidote) both increase QTc interval. Avoid or Use Alternate Drug.

• perphenazine

  perphenazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• pramipexole

  trifluoperazine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.

• prochlorperazine

  prochlorperazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• promazine

  promazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• promethazine

  promethazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• protriptyline

  trifluoperazine and protriptyline both increase QTc interval. Avoid or Use Alternate Drug.

• quinidine

  quinidine, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive cardiac effects.

• ropinirole

  trifluoperazine decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.

• safinamide

  trifluoperazine decreases effects of safinamide by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Dopamine antagonists may decrease safinamide effects and exacerbate Parkinson disease symptoms.

• selinexor

  selinexor, trifluoperazine. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

• sodium oxybate

  trifluoperazine, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• sufentanil SL

  sufentanil SL, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• thioridazine

  thioridazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• trazodone

  trifluoperazine and trazodone both increase QTc interval. Avoid or Use Alternate Drug.

• tretinoin

  trifluoperazine, tretinoin. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• tretinoin topical

  trifluoperazine, tretinoin topical. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• trimipramine

  trifluoperazine and trimipramine both increase QTc interval. Avoid or Use Alternate Drug.

• yohimbe

  yohimbe decreases effects of trifluoperazine by pharmacodynamic antagonism. Contraindicated.

• ziprasidone

  trifluoperazine and ziprasidone both increase QTc interval. Avoid or Use Alternate Drug.

Monitor Closely (319)

• abobotulinumtoxinA

  abobotulinumtoxinA increases effects of trifluoperazine by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• aclidinium

  aclidinium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of aclidinium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• albiglutide

  trifluoperazine, albiglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• albuterol

  trifluoperazine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• alfentanil

  alfentanil and trifluoperazine both increase sedation. Use Caution/Monitor.

• almotriptan

  almotriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• alprazolam

  alprazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• amifampridine

  trifluoperazine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.

• amisulpride

  trifluoperazine and amisulpride both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended if coadministered.

• amitriptyline

  trifluoperazine and amitriptyline both increase sedation. Use Caution/Monitor.

• amobarbital

  amobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• amoxapine

  trifluoperazine and amoxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.
  
  trifluoperazine and amoxapine both increase sedation. Use Caution/Monitor.

• anticholinergic/sedative combos

  anticholinergic/sedative combos decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  anticholinergic/sedative combos decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• apomorphine

  trifluoperazine and apomorphine both increase sedation. Use Caution/Monitor.

• arformoterol

  trifluoperazine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• aripiprazole

  aripiprazole and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  aripiprazole and trifluoperazine both increase sedation. Use Caution/Monitor.

• armodafinil

  trifluoperazine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• artemether/lumefantrine

  artemether/lumefantrine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• atracurium

  atracurium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atracurium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine

  atropine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of atropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine IV/IM

  trifluoperazine increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  atropine IV/IM decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine IV/IM decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.

• azelastine

  azelastine and trifluoperazine both increase sedation. Use Caution/Monitor.

• azithromycin

  trifluoperazine and azithromycin both increase QTc interval. Use Caution/Monitor.

• baclofen

  baclofen and trifluoperazine both increase sedation. Use Caution/Monitor.

• belladonna alkaloids

  belladonna alkaloids decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna alkaloids decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• belladonna and opium

  belladonna and opium and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  belladonna and opium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna and opium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• benperidol

  benperidol and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  benperidol and trifluoperazine both increase sedation. Use Caution/Monitor.

• benzphetamine

  trifluoperazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• benztropine

  trifluoperazine increases effects of benztropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. .

• brexanolone

  brexanolone, trifluoperazine. Either increases toxicity of the other by sedation. Use Caution/Monitor.

• brompheniramine

  brompheniramine and trifluoperazine both increase sedation. Use Caution/Monitor.

• buprenorphine

  buprenorphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• buprenorphine buccal

  buprenorphine buccal and trifluoperazine both increase sedation. Use Caution/Monitor.

• buprenorphine, long-acting injection

  trifluoperazine increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

• bupropion

  bupropion will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• butabarbital

  butabarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• butalbital

  butalbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• butorphanol

  butorphanol and trifluoperazine both increase sedation. Use Caution/Monitor.

• caffeine

  trifluoperazine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• cannabidiol

  cannabidiol, trifluoperazine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.

• carbinoxamine

  carbinoxamine and trifluoperazine both increase sedation. Use Caution/Monitor.

• carisoprodol

  carisoprodol and trifluoperazine both increase sedation. Use Caution/Monitor.

• cenobamate

  cenobamate, trifluoperazine. Either increases effects of the other by sedation. Use Caution/Monitor.

• chloral hydrate

  chloral hydrate and trifluoperazine both increase sedation. Use Caution/Monitor.

• chlordiazepoxide

  chlordiazepoxide and trifluoperazine both increase sedation. Use Caution/Monitor.

• chlorpheniramine

  chlorpheniramine and trifluoperazine both increase sedation. Use Caution/Monitor.

• chlorpromazine

  chlorpromazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and trifluoperazine both increase sedation. Use Caution/Monitor.

• chlorzoxazone

  chlorzoxazone and trifluoperazine both increase sedation. Use Caution/Monitor.

• cigarette smoking

  cigarette smoking decreases levels of trifluoperazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• cinnarizine

  cinnarizine and trifluoperazine both increase sedation. Use Caution/Monitor.

• cisatracurium

  cisatracurium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cisatracurium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• clemastine

  clemastine and trifluoperazine both increase sedation. Use Caution/Monitor.

• clomipramine

  trifluoperazine and clomipramine both increase sedation. Use Caution/Monitor.

• clonazepam

  clonazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• clonidine

  clonidine, trifluoperazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• clorazepate

  clorazepate and trifluoperazine both increase sedation. Use Caution/Monitor.

• clozapine

  clozapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  clozapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• codeine

  codeine and trifluoperazine both increase sedation. Use Caution/Monitor.

• cyclizine

  cyclizine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  cyclizine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclizine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of cyclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cyclobenzaprine

  cyclobenzaprine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  cyclobenzaprine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclobenzaprine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of cyclobenzaprine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• cyproheptadine

  cyproheptadine and trifluoperazine both increase sedation. Use Caution/Monitor.

• dantrolene

  dantrolene and trifluoperazine both increase sedation. Use Caution/Monitor.

• daridorexant

  trifluoperazine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• darifenacin

  darifenacin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• dasatinib

  trifluoperazine and dasatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• desflurane

  desflurane and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  desflurane and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• desipramine

  trifluoperazine and desipramine both increase sedation. Use Caution/Monitor.

• desvenlafaxine

  desvenlafaxine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg

• deutetrabenazine

  trifluoperazine and deutetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely. The risk for parkinsonism, neuroleptic malignant syndrome, and akathisia may be increased by concomitant use of deutetrabenazine and dopamine antagonists or antipsychotics.
  
  trifluoperazine and deutetrabenazine both increase sedation. Use Caution/Monitor.
  
  deutetrabenazine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• dexchlorpheniramine

  dexchlorpheniramine and trifluoperazine both increase sedation. Use Caution/Monitor.

• dexfenfluramine

  trifluoperazine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, dexfenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dexmedetomidine

  dexmedetomidine and trifluoperazine both increase sedation. Use Caution/Monitor.

• dexmethylphenidate

  trifluoperazine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dextroamphetamine

  trifluoperazine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, dextroamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dextromethorphan

  dextromethorphan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• dextromoramide

  dextromoramide and trifluoperazine both increase sedation. Use Caution/Monitor.

• diamorphine

  diamorphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• diazepam

  diazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• dicyclomine

  dicyclomine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  dicyclomine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of dicyclomine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diethylpropion

  trifluoperazine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, diethylpropion. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• difelikefalin

  difelikefalin and trifluoperazine both increase sedation. Use Caution/Monitor.

• difenoxin hcl

  difenoxin hcl and trifluoperazine both increase sedation. Use Caution/Monitor.

• dihydroergotamine

  dihydroergotamine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• dimenhydrinate

  dimenhydrinate and trifluoperazine both increase sedation. Use Caution/Monitor.

• diphenhydramine

  diphenhydramine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  diphenhydramine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  diphenhydramine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diphenoxylate hcl

  diphenoxylate hcl and trifluoperazine both increase sedation. Use Caution/Monitor.

• dipipanone

  dipipanone and trifluoperazine both increase sedation. Use Caution/Monitor.

• dobutamine

  trifluoperazine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, dobutamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dolasetron

  trifluoperazine and dolasetron both increase QTc interval. Modify Therapy/Monitor Closely.

• donepezil

  donepezil and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• donepezil transdermal

  donepezil transdermal, trifluoperazine. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.

• dopamine

  trifluoperazine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, dopamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• dopexamine

  trifluoperazine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dosulepin

  trifluoperazine and dosulepin both increase sedation. Use Caution/Monitor.

• doxepin

  trifluoperazine and doxepin both increase sedation. Use Caution/Monitor.

• doxylamine

  doxylamine and trifluoperazine both increase sedation. Use Caution/Monitor.

• droperidol

  droperidol and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  droperidol and trifluoperazine both increase sedation. Use Caution/Monitor.

• efavirenz

  efavirenz and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• eletriptan

  eletriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• encorafenib

  encorafenib and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• entrectinib

  entrectinib and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• ephedrine

  trifluoperazine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, ephedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• epinephrine

  trifluoperazine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, epinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine decreases effects of epinephrine by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.

• epinephrine racemic

  trifluoperazine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.

• ergoloid mesylates

  ergoloid mesylates, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• ergotamine

  ergotamine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• eribulin

  eribulin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• esketamine intranasal

  esketamine intranasal, trifluoperazine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• estazolam

  estazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• ethanol

  trifluoperazine and ethanol both increase sedation. Use Caution/Monitor.

• etomidate

  etomidate and trifluoperazine both increase sedation. Use Caution/Monitor.

• fenfluramine

  trifluoperazine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, fenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• fentanyl

  fentanyl, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• fesoterodine

  fesoterodine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  fesoterodine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• fexinidazole

  fexinidazole will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• fingolimod

  fingolimod and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• flavoxate

  flavoxate decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  flavoxate decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of flavoxate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• flecainide

  trifluoperazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.

• flibanserin

  flibanserin, trifluoperazine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• fluoxetine

  fluoxetine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  trifluoperazine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.

• fluphenazine

  fluphenazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  fluphenazine and trifluoperazine both increase sedation. Use Caution/Monitor.

• flurazepam

  flurazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• fluvoxamine

  fluvoxamine and trifluoperazine both increase QTc interval. Modify Therapy/Monitor Closely.

• formoterol

  trifluoperazine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• foscarnet

  trifluoperazine and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.

• frovatriptan

  frovatriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• ganaxolone

  trifluoperazine and ganaxolone both increase sedation. Use Caution/Monitor.

• gemifloxacin

  gemifloxacin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• gilteritinib

  gilteritinib and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• glycopyrrolate

  trifluoperazine increases effects of glycopyrrolate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• glycopyrrolate inhaled

  glycopyrrolate inhaled decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  glycopyrrolate inhaled decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• glycopyrronium tosylate topical

  glycopyrronium tosylate topical, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.

• granisetron

  granisetron and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• guanfacine

  guanfacine, trifluoperazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• haloperidol

  haloperidol and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  haloperidol and trifluoperazine both increase sedation. Use Caution/Monitor.

• henbane

  henbane decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  henbane decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of henbane by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• homatropine

  homatropine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  homatropine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of homatropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hydromorphone

  hydromorphone and trifluoperazine both increase sedation. Use Caution/Monitor.

• hydroxyzine

  hydroxyzine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  hydroxyzine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• hyoscyamine

  hyoscyamine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hyoscyamine spray

  trifluoperazine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  hyoscyamine spray decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine spray decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.

• iloperidone

  iloperidone and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  trifluoperazine and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  iloperidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• imipramine

  trifluoperazine and imipramine both increase sedation. Use Caution/Monitor.

• incobotulinumtoxinA

  trifluoperazine increases effects of incobotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• indacaterol, inhaled

  indacaterol, inhaled, trifluoperazine. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.

• insulin degludec

  trifluoperazine decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin degludec/insulin aspart

  trifluoperazine decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin inhaled

  trifluoperazine decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• ipratropium

  ipratropium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  ipratropium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of ipratropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• isoflurane

  isoflurane and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• isoproterenol

  trifluoperazine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, isoproterenol. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• ketamine

  ketamine and trifluoperazine both increase sedation. Use Caution/Monitor.

• ketotifen, ophthalmic

  trifluoperazine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

• lapatinib

  trifluoperazine and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• lasmiditan

  lasmiditan, trifluoperazine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

• lemborexant

  lemborexant, trifluoperazine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

• levalbuterol

  trifluoperazine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• levofloxacin

  trifluoperazine and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• levomilnacipran

  levomilnacipran, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• levorphanol

  levorphanol and trifluoperazine both increase sedation. Use Caution/Monitor.

• linezolid

  linezolid, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• liraglutide

  trifluoperazine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• lisdexamfetamine

  trifluoperazine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, lisdexamfetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• lithium

  lithium, trifluoperazine. Other (see comment). Use Caution/Monitor. Comment: Risk of neurotoxicity. Multiple mechanisms involved.
  
  lithium, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  lithium and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• lofepramine

  trifluoperazine and lofepramine both increase sedation. Use Caution/Monitor.

• lofexidine

  trifluoperazine and lofexidine both increase sedation. Use Caution/Monitor.

• loprazolam

  loprazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• lorazepam

  lorazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• lorcaserin

  lorcaserin, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• lormetazepam

  lormetazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• loxapine

  loxapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  loxapine inhaled and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine inhaled and trifluoperazine both increase sedation. Use Caution/Monitor.

• lumefantrine

  lumefantrine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• lurasidone

  lurasidone, trifluoperazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.

• maprotiline

  trifluoperazine and maprotiline both increase sedation. Use Caution/Monitor.

• marijuana

  trifluoperazine and marijuana both increase sedation. Use Caution/Monitor.

• meclizine

  meclizine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  meclizine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• melatonin

  trifluoperazine and melatonin both increase sedation. Use Caution/Monitor.

• meperidine

  meperidine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  meperidine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• meprobamate

  trifluoperazine and meprobamate both increase sedation. Use Caution/Monitor.

• metaproterenol

  trifluoperazine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• metaxalone

  metaxalone and trifluoperazine both increase sedation. Use Caution/Monitor.

• metformin

  trifluoperazine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.

• methadone

  trifluoperazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  methadone and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  methadone, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• methamphetamine

  trifluoperazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, methamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• methocarbamol

  methocarbamol and trifluoperazine both increase sedation. Use Caution/Monitor.

• methoxsalen

  methoxsalen, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.

• methscopolamine

  methscopolamine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  methscopolamine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• methylenedioxymethamphetamine

  trifluoperazine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, methylenedioxymethamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• methylergonovine

  methylergonovine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• methylphenidate

  trifluoperazine, methylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases toxicity of methylphenidate by pharmacodynamic antagonism. Use Caution/Monitor. Closely monitor for signs of altered clinical response to either methylphenidate or an antipsychotic when using these drugs in combination.

• metoclopramide

  trifluoperazine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.

• midazolam

  midazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  midazolam intranasal, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

  trifluoperazine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, midodrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• milnacipran

  milnacipran, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• mirtazapine

  trifluoperazine and mirtazapine both increase sedation. Use Caution/Monitor.
  
  mirtazapine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• modafinil

  trifluoperazine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• morphine

  morphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• motherwort

  trifluoperazine and motherwort both increase sedation. Use Caution/Monitor.

• moxonidine

  trifluoperazine and moxonidine both increase sedation. Use Caution/Monitor.

• nabilone

  trifluoperazine and nabilone both increase sedation. Use Caution/Monitor.

• nalbuphine

  nalbuphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• naratriptan

  naratriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• norepinephrine

  trifluoperazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, norepinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• nortriptyline

  trifluoperazine and nortriptyline both increase sedation. Use Caution/Monitor.

• ofloxacin

  trifluoperazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• olanzapine

  olanzapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  olanzapine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• oliceridine

  oliceridine, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• olodaterol inhaled

  trifluoperazine and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias

• onabotulinumtoxinA

  onabotulinumtoxinA decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  onabotulinumtoxinA decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• opium tincture

  opium tincture and trifluoperazine both increase sedation. Use Caution/Monitor.

• orphenadrine

  orphenadrine and trifluoperazine both increase sedation. Use Caution/Monitor.

• oxaliplatin

  oxaliplatin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• oxazepam

  oxazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• oxybutynin

  oxybutynin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin topical

  oxybutynin topical decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin topical decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxybutynin transdermal

  oxybutynin transdermal decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin transdermal decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• oxycodone

  oxycodone and trifluoperazine both increase sedation. Use Caution/Monitor.

• oxymorphone

  oxymorphone and trifluoperazine both increase sedation. Use Caution/Monitor.

• paliperidone

  paliperidone and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  trifluoperazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  paliperidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• pancuronium

  pancuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pancuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• papaveretum

  papaveretum and trifluoperazine both increase sedation. Use Caution/Monitor.

• papaverine

  trifluoperazine and papaverine both increase sedation. Use Caution/Monitor.

• paroxetine

  paroxetine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  trifluoperazine and paroxetine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  paroxetine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• pazopanib

  trifluoperazine and pazopanib both increase QTc interval. Use Caution/Monitor.

• pentazocine

  pentazocine and trifluoperazine both increase sedation. Use Caution/Monitor.

• pentobarbital

  pentobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• perphenazine

  perphenazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  perphenazine and trifluoperazine both increase sedation. Use Caution/Monitor.

• phendimetrazine

  trifluoperazine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, phendimetrazine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• phenelzine

  phenelzine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• phenobarbital

  phenobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• phentermine

  trifluoperazine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, phentermine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• phenylephrine

  trifluoperazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• phenylephrine PO

  trifluoperazine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
  
  trifluoperazine, phenylephrine PO. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• pholcodine

  trifluoperazine and pholcodine both increase sedation. Use Caution/Monitor.

• pimozide

  pimozide and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  pimozide and trifluoperazine both increase sedation. Use Caution/Monitor.

• pirbuterol

  trifluoperazine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• porfimer

  trifluoperazine, porfimer. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Enhanced photosensitivity.

• posaconazole

  trifluoperazine and posaconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• pralidoxime

  pralidoxime decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pralidoxime decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• primaquine

  primaquine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• primidone

  primidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• procarbazine

  procarbazine, trifluoperazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Excessive sedation.
  
  procarbazine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• prochlorperazine

  prochlorperazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  prochlorperazine and trifluoperazine both increase sedation. Use Caution/Monitor.

• promethazine

  promethazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  promethazine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  promethazine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• propafenone

  propafenone will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• propantheline

  propantheline decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  propantheline decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• propofol

  propofol and trifluoperazine both increase sedation. Use Caution/Monitor.

• propylhexedrine

  trifluoperazine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, propylhexedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• protriptyline

  trifluoperazine and protriptyline both increase sedation. Use Caution/Monitor.

• pseudoephedrine

  trifluoperazine, pseudoephedrine. Mechanism: unknown. Use Caution/Monitor. Consider avoiding use of pseudoephedrine in patients receiving phenothiazines (especially thioridazine) due to the potential risk of cardiac arrhythmia or sudden death. Monitor for evidence of ventricular arrhythmias during concomitant use.

• quazepam

  quazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• quetiapine

  quetiapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  quetiapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• quinidine

  quinidine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• ramelteon

  trifluoperazine and ramelteon both increase sedation. Use Caution/Monitor.

• ranolazine

  trifluoperazine and ranolazine both increase QTc interval. Modify Therapy/Monitor Closely.

• rapacuronium

  rapacuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rapacuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• remimazolam

  remimazolam, trifluoperazine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.

• rimabotulinumtoxinB

  trifluoperazine, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.

• risperidone

  risperidone and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  trifluoperazine and risperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  risperidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• rizatriptan

  rizatriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• rocuronium

  rocuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rocuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• romidepsin

  trifluoperazine and romidepsin both increase QTc interval. Modify Therapy/Monitor Closely.

• rucaparib

  rucaparib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP1A2 substrates, if clinically indicated.

• salmeterol

  trifluoperazine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• scopolamine

  scopolamine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  scopolamine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• scullcap

  trifluoperazine and scullcap both increase sedation. Use Caution/Monitor.

• secobarbital

  secobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• selegiline

  selegiline, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• serdexmethylphenidate/dexmethylphenidate

  trifluoperazine, serdexmethylphenidate/dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• sertraline

  sertraline and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• sevoflurane

  sevoflurane and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  sevoflurane and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• shepherd's purse

  trifluoperazine and shepherd's purse both increase sedation. Use Caution/Monitor.

• siponimod

  siponimod and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• smoking

  smoking decreases levels of trifluoperazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• sodium sulfate/?magnesium sulfate/potassium chloride

  sodium sulfate/?magnesium sulfate/potassium chloride increases effects of trifluoperazine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• sodium sulfate/potassium sulfate/magnesium sulfate

  sodium sulfate/potassium sulfate/magnesium sulfate increases effects of trifluoperazine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• solifenacin

  solifenacin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  solifenacin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  solifenacin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• stiripentol

  stiripentol, trifluoperazine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.

• sufentanil

  sufentanil and trifluoperazine both increase sedation. Use Caution/Monitor.

• sulfamethoxazole

  trifluoperazine and sulfamethoxazole both increase QTc interval. Modify Therapy/Monitor Closely.

• sumatriptan

  sumatriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• sumatriptan intranasal

  sumatriptan intranasal, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• tapentadol

  tapentadol and trifluoperazine both increase sedation. Use Caution/Monitor.

• teduglutide

  teduglutide increases levels of trifluoperazine by Other (see comment). Use Caution/Monitor. Comment: Teduglutide may increase absorption of concomitant PO medications; caution with with drugs requiring titration or those with a narrow therapeutic index; dose adjustment may be necessary.

• telavancin

  trifluoperazine and telavancin both increase QTc interval. Modify Therapy/Monitor Closely.

• temazepam

  temazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• terbutaline

  trifluoperazine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• teriflunomide

  teriflunomide decreases levels of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• tetrabenazine

  trifluoperazine and tetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.

• thioridazine

  thioridazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  thioridazine and trifluoperazine both increase sedation. Use Caution/Monitor.

• thiothixene

  thiothixene and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  thiothixene and trifluoperazine both increase sedation. Use Caution/Monitor.

• tiotropium

  tiotropium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tiotropium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of tiotropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• tobacco use

  tobacco use decreases levels of trifluoperazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• tolterodine

  tolterodine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tolterodine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of tolterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• topiramate

  trifluoperazine and topiramate both increase sedation. Modify Therapy/Monitor Closely.

• tramadol

  tramadol and trifluoperazine both increase sedation. Use Caution/Monitor.

• tranylcypromine

  tranylcypromine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• trazodone

  trifluoperazine and trazodone both increase sedation. Use Caution/Monitor.

• triazolam

  triazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• triclofos

  triclofos and trifluoperazine both increase sedation. Use Caution/Monitor.

• trihexyphenidyl

  trihexyphenidyl decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimethoprim

  trifluoperazine and trimethoprim both increase QTc interval. Modify Therapy/Monitor Closely.

• trimipramine

  trifluoperazine and trimipramine both increase sedation. Use Caution/Monitor.

• triprolidine

  triprolidine and trifluoperazine both increase sedation. Use Caution/Monitor.

• tropisetron

  trifluoperazine and tropisetron both increase QTc interval. Modify Therapy/Monitor Closely.

• trospium chloride

  trospium chloride decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  trospium chloride decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• vecuronium

  vecuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  vecuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• venlafaxine

  venlafaxine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
  
  trifluoperazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• vilazodone

  vilazodone, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• voriconazole

  trifluoperazine and voriconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• xylometazoline

  trifluoperazine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, xylometazoline. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• yohimbine

  trifluoperazine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
  
  trifluoperazine, yohimbine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• ziconotide

  trifluoperazine and ziconotide both increase sedation. Use Caution/Monitor.

• ziprasidone

  trifluoperazine and ziprasidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  trifluoperazine and ziprasidone both increase sedation. Use Caution/Monitor.

• zolmitriptan

  zolmitriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• zolpidem

  trifluoperazine will increase the level or effect of zolpidem by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Additive effect of decreased alertness and psychomotor performance

• zotepine

  trifluoperazine and zotepine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  trifluoperazine and zotepine both increase sedation. Use Caution/Monitor.

Minor (61)

• amiodarone

  amiodarone will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• amitriptyline

  amitriptyline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amitriptyline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• amoxapine

  amoxapine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amoxapine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• asenapine

  asenapine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• atropine

  trifluoperazine increases toxicity of atropine by unknown mechanism. Minor/Significance Unknown.

• atropine IV/IM

  trifluoperazine increases toxicity of atropine IV/IM by unknown mechanism. Minor/Significance Unknown.

• benazepril

  trifluoperazine increases effects of benazepril by unspecified interaction mechanism. Minor/Significance Unknown. Enhanced hypotensive effects.

• brimonidine

  brimonidine increases effects of trifluoperazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• bupropion

  trifluoperazine increases toxicity of bupropion by unspecified interaction mechanism. Minor/Significance Unknown. May lower seizure threshold; keep bupropion dose as low as possible.

• captopril

  trifluoperazine increases effects of captopril by unspecified interaction mechanism. Minor/Significance Unknown. Both drugs lower blood pressure. Monitor blood pressure.

• celecoxib

  celecoxib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• chasteberry

  chasteberry decreases effects of trifluoperazine by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).

• chloroquine

  chloroquine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  chloroquine increases levels of trifluoperazine by decreasing metabolism. Minor/Significance Unknown.

• cimetidine

  cimetidine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• clomipramine

  clomipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  clomipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• darifenacin

  darifenacin will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• desipramine

  desipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  desipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• diphenhydramine

  diphenhydramine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• doxepin

  doxepin, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  doxepin, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• dronedarone

  dronedarone will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• duloxetine

  duloxetine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• enalapril

  trifluoperazine increases effects of enalapril by unspecified interaction mechanism. Minor/Significance Unknown.

• ethanol

  ethanol, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.

• eucalyptus

  trifluoperazine and eucalyptus both increase sedation. Minor/Significance Unknown.

• fosinopril

  trifluoperazine increases effects of fosinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• glycopyrrolate

  trifluoperazine increases toxicity of glycopyrrolate by unknown mechanism. Minor/Significance Unknown.

• glycopyrrolate inhaled

  trifluoperazine increases toxicity of glycopyrrolate inhaled by unknown mechanism. Minor/Significance Unknown.

• haloperidol

  haloperidol will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• imatinib

  imatinib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• imidapril

  trifluoperazine increases effects of imidapril by unspecified interaction mechanism. Minor/Significance Unknown.

• imipramine

  imipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  imipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• lisinopril

  trifluoperazine increases effects of lisinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• lofepramine

  lofepramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  lofepramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• maprotiline

  maprotiline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  maprotiline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• maraviroc

  maraviroc will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• marijuana

  marijuana will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• metyrapone

  trifluoperazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.

• metyrosine

  metyrosine increases toxicity of trifluoperazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased extrapyramidal symptoms.

• moexipril

  trifluoperazine increases effects of moexipril by unspecified interaction mechanism. Minor/Significance Unknown.

• nilotinib

  nilotinib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• nortriptyline

  nortriptyline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  nortriptyline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• oxybutynin

  oxybutynin increases toxicity of trifluoperazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin topical

  oxybutynin topical increases toxicity of trifluoperazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin transdermal

  oxybutynin transdermal increases toxicity of trifluoperazine by unspecified interaction mechanism. Minor/Significance Unknown.

• parecoxib

  parecoxib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• perindopril

  trifluoperazine increases effects of perindopril by unspecified interaction mechanism. Minor/Significance Unknown.

• perphenazine

  perphenazine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• protriptyline

  protriptyline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  protriptyline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• pyrimethamine

  pyrimethamine increases levels of trifluoperazine by decreasing metabolism. Minor/Significance Unknown.

• quinacrine

  quinacrine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• quinapril

  trifluoperazine increases effects of quinapril by unspecified interaction mechanism. Minor/Significance Unknown.

• ramipril

  trifluoperazine increases effects of ramipril by unspecified interaction mechanism. Minor/Significance Unknown.

• ranolazine

  ranolazine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• ritonavir

  ritonavir will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• sage

  trifluoperazine and sage both increase sedation. Minor/Significance Unknown.

• sertraline

  sertraline will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• thioridazine

  thioridazine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tipranavir

  tipranavir will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• trandolapril

  trifluoperazine increases effects of trandolapril by unspecified interaction mechanism. Minor/Significance Unknown.

• trazodone

  trazodone, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.
  
  trazodone, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.

• trimipramine

  trimipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  trimipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• abametapir

  Serious - Use Alternative (1)abametapir will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.

• abobotulinumtoxinA

  Monitor Closely (1)abobotulinumtoxinA increases effects of trifluoperazine by pharmacodynamic synergism. Use Caution/Monitor. Use of anticholinergic drugs after administration of botulinum toxin-containing products may potentiate systemic anticholinergic effects.

• aclidinium

  Monitor Closely (2)aclidinium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of aclidinium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• albiglutide

  Monitor Closely (1)trifluoperazine, albiglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• albuterol

  Monitor Closely (1)trifluoperazine increases and albuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• alfentanil

  Monitor Closely (1)alfentanil and trifluoperazine both increase sedation. Use Caution/Monitor.

• almotriptan

  Monitor Closely (1)almotriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• alprazolam

  Monitor Closely (1)alprazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• amifampridine

  Monitor Closely (1)trifluoperazine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.

• aminolevulinic acid oral

  Serious - Use Alternative (1)aminolevulinic acid oral, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid administering other phototoxic drugs with aminolevulinic acid oral for 24 hr during perioperative period.

• aminolevulinic acid topical

  Serious - Use Alternative (1)trifluoperazine increases toxicity of aminolevulinic acid topical by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration of photosensitizing drugs may enhance the phototoxic reaction to photodynamic therapy with aminolevulinic acid.

• amiodarone

  Serious - Use Alternative (1)trifluoperazine and amiodarone both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)amiodarone will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• amisulpride

  Contraindicated (1)amisulpride, trifluoperazine. Either increases toxicity of the other by Other (see comment). Contraindicated. Comment: Increases risk of neuroleptic malignant syndrome.Monitor Closely (1)trifluoperazine and amisulpride both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended if coadministered.

• amitriptyline

  Monitor Closely (1)trifluoperazine and amitriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and amitriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)amitriptyline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amitriptyline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• amobarbital

  Monitor Closely (1)amobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• amoxapine

  Monitor Closely (2)trifluoperazine and amoxapine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.
  
  trifluoperazine and amoxapine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and amoxapine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)amoxapine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  amoxapine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• anticholinergic/sedative combos

  Monitor Closely (3)anticholinergic/sedative combos decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  anticholinergic/sedative combos decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• apomorphine

  Monitor Closely (1)trifluoperazine and apomorphine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine decreases effects of apomorphine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• arformoterol

  Monitor Closely (1)trifluoperazine increases and arformoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• aripiprazole

  Monitor Closely (2)aripiprazole and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  aripiprazole and trifluoperazine both increase sedation. Use Caution/Monitor.

• armodafinil

  Monitor Closely (1)trifluoperazine increases and armodafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• arsenic trioxide

  Serious - Use Alternative (1)trifluoperazine and arsenic trioxide both increase QTc interval. Avoid or Use Alternate Drug.

• artemether/lumefantrine

  Monitor Closely (1)artemether/lumefantrine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and artemether/lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• asenapine

  Minor (1)asenapine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• atracurium

  Monitor Closely (3)atracurium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atracurium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of atracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• atropine

  Monitor Closely (3)atropine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of atropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)trifluoperazine increases toxicity of atropine by unknown mechanism. Minor/Significance Unknown.

• atropine IV/IM

  Monitor Closely (3)trifluoperazine increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  atropine IV/IM decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  atropine IV/IM decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.Minor (1)trifluoperazine increases toxicity of atropine IV/IM by unknown mechanism. Minor/Significance Unknown.

• azelastine

  Monitor Closely (1)azelastine and trifluoperazine both increase sedation. Use Caution/Monitor.

• azithromycin

  Monitor Closely (1)trifluoperazine and azithromycin both increase QTc interval. Use Caution/Monitor.

• baclofen

  Monitor Closely (1)baclofen and trifluoperazine both increase sedation. Use Caution/Monitor.

• belladonna alkaloids

  Monitor Closely (3)belladonna alkaloids decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna alkaloids decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• belladonna and opium

  Monitor Closely (4)belladonna and opium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  belladonna and opium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  belladonna and opium and trifluoperazine both increase sedation. Use Caution/Monitor.

• benazepril

  Minor (1)trifluoperazine increases effects of benazepril by unspecified interaction mechanism. Minor/Significance Unknown. Enhanced hypotensive effects.

• benperidol

  Monitor Closely (2)benperidol and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  benperidol and trifluoperazine both increase sedation. Use Caution/Monitor.

• benzhydrocodone/acetaminophen

  Serious - Use Alternative (1)benzhydrocodone/acetaminophen, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• benzphetamine

  Monitor Closely (2)trifluoperazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• benztropine

  Monitor Closely (1)trifluoperazine increases effects of benztropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic adverse effects may be seen with concurrent use. .

• brexanolone

  Monitor Closely (1)brexanolone, trifluoperazine. Either increases toxicity of the other by sedation. Use Caution/Monitor.

• brimonidine

  Minor (1)brimonidine increases effects of trifluoperazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.

• bromocriptine

  Serious - Use Alternative (1)trifluoperazine decreases effects of bromocriptine by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• brompheniramine

  Monitor Closely (1)brompheniramine and trifluoperazine both increase sedation. Use Caution/Monitor.

• buprenorphine

  Monitor Closely (1)buprenorphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• buprenorphine buccal

  Monitor Closely (1)buprenorphine buccal and trifluoperazine both increase sedation. Use Caution/Monitor.

• buprenorphine, long-acting injection

  Monitor Closely (1)trifluoperazine increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.

• bupropion

  Monitor Closely (1)bupropion will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Minor (1)trifluoperazine increases toxicity of bupropion by unspecified interaction mechanism. Minor/Significance Unknown. May lower seizure threshold; keep bupropion dose as low as possible.

• butabarbital

  Monitor Closely (1)butabarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• butalbital

  Monitor Closely (1)butalbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• butorphanol

  Monitor Closely (1)butorphanol and trifluoperazine both increase sedation. Use Caution/Monitor.

• cabergoline

  Serious - Use Alternative (1)trifluoperazine decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.

• caffeine

  Monitor Closely (1)trifluoperazine increases and caffeine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• calcium/magnesium/potassium/sodium oxybates

  Serious - Use Alternative (1)trifluoperazine, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• cannabidiol

  Monitor Closely (1)cannabidiol, trifluoperazine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.

• captopril

  Minor (1)trifluoperazine increases effects of captopril by unspecified interaction mechanism. Minor/Significance Unknown. Both drugs lower blood pressure. Monitor blood pressure.

• carbinoxamine

  Monitor Closely (1)carbinoxamine and trifluoperazine both increase sedation. Use Caution/Monitor.

• carisoprodol

  Monitor Closely (1)carisoprodol and trifluoperazine both increase sedation. Use Caution/Monitor.

• celecoxib

  Minor (1)celecoxib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• cenobamate

  Monitor Closely (1)cenobamate, trifluoperazine. Either increases effects of the other by sedation. Use Caution/Monitor.

• chasteberry

  Minor (1)chasteberry decreases effects of trifluoperazine by pharmacodynamic antagonism. Minor/Significance Unknown. (Theoretical interaction).

• chloral hydrate

  Monitor Closely (1)chloral hydrate and trifluoperazine both increase sedation. Use Caution/Monitor.

• chlordiazepoxide

  Monitor Closely (1)chlordiazepoxide and trifluoperazine both increase sedation. Use Caution/Monitor.

• chloroquine

  Minor (2)chloroquine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
  
  chloroquine increases levels of trifluoperazine by decreasing metabolism. Minor/Significance Unknown.

• chlorpheniramine

  Monitor Closely (1)chlorpheniramine and trifluoperazine both increase sedation. Use Caution/Monitor.

• chlorpromazine

  Monitor Closely (2)chlorpromazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  chlorpromazine and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)chlorpromazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• chlorzoxazone

  Monitor Closely (1)chlorzoxazone and trifluoperazine both increase sedation. Use Caution/Monitor.

• cigarette smoking

  Monitor Closely (1)cigarette smoking decreases levels of trifluoperazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• cimetidine

  Minor (1)cimetidine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• cinnarizine

  Monitor Closely (1)cinnarizine and trifluoperazine both increase sedation. Use Caution/Monitor.

• cisatracurium

  Monitor Closely (3)cisatracurium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cisatracurium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of cisatracurium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• clarithromycin

  Serious - Use Alternative (1)trifluoperazine and clarithromycin both increase QTc interval. Avoid or Use Alternate Drug.

• clemastine

  Monitor Closely (1)clemastine and trifluoperazine both increase sedation. Use Caution/Monitor.

• clomipramine

  Monitor Closely (1)trifluoperazine and clomipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and clomipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)clomipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  clomipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• clonazepam

  Monitor Closely (1)clonazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• clonidine

  Monitor Closely (1)clonidine, trifluoperazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• clorazepate

  Monitor Closely (1)clorazepate and trifluoperazine both increase sedation. Use Caution/Monitor.

• clozapine

  Monitor Closely (2)clozapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  clozapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• codeine

  Monitor Closely (1)codeine and trifluoperazine both increase sedation. Use Caution/Monitor.

• cyclizine

  Monitor Closely (4)cyclizine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclizine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of cyclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  cyclizine and trifluoperazine both increase sedation. Use Caution/Monitor.

• cyclobenzaprine

  Monitor Closely (4)cyclobenzaprine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  cyclobenzaprine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of cyclobenzaprine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  cyclobenzaprine and trifluoperazine both increase sedation. Use Caution/Monitor.

• cyproheptadine

  Monitor Closely (1)cyproheptadine and trifluoperazine both increase sedation. Use Caution/Monitor.

• dantrolene

  Monitor Closely (1)dantrolene and trifluoperazine both increase sedation. Use Caution/Monitor.

• daridorexant

  Monitor Closely (1)trifluoperazine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.

• darifenacin

  Monitor Closely (3)darifenacin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  darifenacin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of darifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)darifenacin will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• dasatinib

  Monitor Closely (1)trifluoperazine and dasatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• degarelix

  Serious - Use Alternative (1)degarelix and trifluoperazine both decrease QTc interval. Avoid or Use Alternate Drug.

• desflurane

  Monitor Closely (2)desflurane and trifluoperazine both decrease QTc interval. Use Caution/Monitor.
  
  desflurane and trifluoperazine both increase sedation. Use Caution/Monitor.

• desipramine

  Monitor Closely (1)trifluoperazine and desipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and desipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)desipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  desipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• desvenlafaxine

  Monitor Closely (1)desvenlafaxine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg

• deutetrabenazine

  Monitor Closely (3)trifluoperazine and deutetrabenazine both increase sedation. Use Caution/Monitor.
  
  trifluoperazine and deutetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely. The risk for parkinsonism, neuroleptic malignant syndrome, and akathisia may be increased by concomitant use of deutetrabenazine and dopamine antagonists or antipsychotics.
  
  deutetrabenazine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• dexchlorpheniramine

  Monitor Closely (1)dexchlorpheniramine and trifluoperazine both increase sedation. Use Caution/Monitor.

• dexfenfluramine

  Monitor Closely (2)trifluoperazine, dexfenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dexmedetomidine

  Monitor Closely (1)dexmedetomidine and trifluoperazine both increase sedation. Use Caution/Monitor.

• dexmethylphenidate

  Monitor Closely (2)trifluoperazine, dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextroamphetamine

  Monitor Closely (2)trifluoperazine, dextroamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dextromethorphan

  Monitor Closely (1)dextromethorphan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• dextromoramide

  Monitor Closely (1)dextromoramide and trifluoperazine both increase sedation. Use Caution/Monitor.

• diamorphine

  Monitor Closely (1)diamorphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• diazepam

  Monitor Closely (1)diazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• dicyclomine

  Monitor Closely (3)dicyclomine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  dicyclomine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of dicyclomine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• diethylpropion

  Monitor Closely (2)trifluoperazine, diethylpropion. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and diethylpropion decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• difelikefalin

  Monitor Closely (1)difelikefalin and trifluoperazine both increase sedation. Use Caution/Monitor.

• difenoxin hcl

  Monitor Closely (1)difenoxin hcl and trifluoperazine both increase sedation. Use Caution/Monitor.

• dihydroergotamine

  Monitor Closely (1)dihydroergotamine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• dimenhydrinate

  Monitor Closely (1)dimenhydrinate and trifluoperazine both increase sedation. Use Caution/Monitor.

• diphenhydramine

  Monitor Closely (4)diphenhydramine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  diphenhydramine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of diphenhydramine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  diphenhydramine and trifluoperazine both increase sedation. Use Caution/Monitor.Minor (1)diphenhydramine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• diphenoxylate hcl

  Monitor Closely (1)diphenoxylate hcl and trifluoperazine both increase sedation. Use Caution/Monitor.

• dipipanone

  Monitor Closely (1)dipipanone and trifluoperazine both increase sedation. Use Caution/Monitor.

• disopyramide

  Contraindicated (1)trifluoperazine and disopyramide both increase QTc interval. Contraindicated.

• dobutamine

  Monitor Closely (2)trifluoperazine, dobutamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and dobutamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dofetilide

  Serious - Use Alternative (1)trifluoperazine and dofetilide both increase QTc interval. Avoid or Use Alternate Drug.

• dolasetron

  Monitor Closely (1)trifluoperazine and dolasetron both increase QTc interval. Modify Therapy/Monitor Closely.

• donepezil

  Monitor Closely (1)donepezil and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• donepezil transdermal

  Monitor Closely (1)donepezil transdermal, trifluoperazine. Either decreases effects of the other by pharmacodynamic antagonism. Use Caution/Monitor.

• dopamine

  Monitor Closely (2)trifluoperazine, dopamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and dopamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.

• dopexamine

  Monitor Closely (1)trifluoperazine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• dosulepin

  Monitor Closely (1)trifluoperazine and dosulepin both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and dosulepin both increase QTc interval. Avoid or Use Alternate Drug.

• doxepin

  Monitor Closely (1)trifluoperazine and doxepin both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and doxepin both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)doxepin, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  doxepin, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• doxylamine

  Monitor Closely (1)doxylamine and trifluoperazine both increase sedation. Use Caution/Monitor.

• dronedarone

  Serious - Use Alternative (1)trifluoperazine and dronedarone both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)dronedarone will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• droperidol

  Monitor Closely (2)droperidol and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  droperidol and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and droperidol both increase QTc interval. Avoid or Use Alternate Drug.

• duloxetine

  Minor (1)duloxetine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• efavirenz

  Monitor Closely (1)efavirenz and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• eletriptan

  Monitor Closely (1)eletriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• enalapril

  Minor (1)trifluoperazine increases effects of enalapril by unspecified interaction mechanism. Minor/Significance Unknown.

• encorafenib

  Monitor Closely (1)encorafenib and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• entrectinib

  Monitor Closely (1)entrectinib and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• ephedrine

  Monitor Closely (2)trifluoperazine, ephedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and ephedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• epinephrine

  Monitor Closely (3)trifluoperazine, epinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine decreases effects of epinephrine by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.
  
  trifluoperazine increases and epinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)epinephrine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• epinephrine racemic

  Monitor Closely (2)trifluoperazine decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.
  
  trifluoperazine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)epinephrine racemic and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• ergoloid mesylates

  Monitor Closely (1)ergoloid mesylates, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• ergotamine

  Monitor Closely (1)ergotamine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• eribulin

  Monitor Closely (1)eribulin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• erythromycin base

  Serious - Use Alternative (1)trifluoperazine and erythromycin base both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin ethylsuccinate

  Serious - Use Alternative (1)trifluoperazine and erythromycin ethylsuccinate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin lactobionate

  Serious - Use Alternative (1)trifluoperazine and erythromycin lactobionate both increase QTc interval. Avoid or Use Alternate Drug.

• erythromycin stearate

  Serious - Use Alternative (1)trifluoperazine and erythromycin stearate both increase QTc interval. Avoid or Use Alternate Drug.

• esketamine intranasal

  Monitor Closely (1)esketamine intranasal, trifluoperazine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.

• estazolam

  Monitor Closely (1)estazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• ethanol

  Monitor Closely (1)trifluoperazine and ethanol both increase sedation. Use Caution/Monitor.Minor (1)ethanol, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive CNS depression.

• etomidate

  Monitor Closely (1)etomidate and trifluoperazine both increase sedation. Use Caution/Monitor.

• eucalyptus

  Minor (1)trifluoperazine and eucalyptus both increase sedation. Minor/Significance Unknown.

• fenfluramine

  Monitor Closely (2)trifluoperazine, fenfluramine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• fentanyl

  Monitor Closely (1)fentanyl, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).Serious - Use Alternative (1)fentanyl, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl intranasal

  Serious - Use Alternative (1)fentanyl intranasal, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transdermal

  Serious - Use Alternative (1)fentanyl transdermal, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fentanyl transmucosal

  Serious - Use Alternative (1)fentanyl transmucosal, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.

• fesoterodine

  Monitor Closely (3)fesoterodine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  fesoterodine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of fesoterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• fexinidazole

  Monitor Closely (1)fexinidazole will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• fingolimod

  Monitor Closely (1)fingolimod and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• flavoxate

  Monitor Closely (3)flavoxate decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  flavoxate decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of flavoxate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• flecainide

  Monitor Closely (1)trifluoperazine and flecainide both increase QTc interval. Modify Therapy/Monitor Closely.

• flibanserin

  Monitor Closely (1)flibanserin, trifluoperazine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• fluconazole

  Serious - Use Alternative (1)trifluoperazine and fluconazole both increase QTc interval. Avoid or Use Alternate Drug.

• fluoxetine

  Monitor Closely (2)trifluoperazine and fluoxetine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  fluoxetine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• fluphenazine

  Monitor Closely (2)fluphenazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  fluphenazine and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)fluphenazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• flurazepam

  Monitor Closely (1)flurazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• fluvoxamine

  Monitor Closely (1)fluvoxamine and trifluoperazine both increase QTc interval. Modify Therapy/Monitor Closely.

• formoterol

  Monitor Closely (1)trifluoperazine increases and formoterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and formoterol both increase QTc interval. Avoid or Use Alternate Drug.

• foscarnet

  Monitor Closely (1)trifluoperazine and foscarnet both increase QTc interval. Modify Therapy/Monitor Closely.

• fosinopril

  Minor (1)trifluoperazine increases effects of fosinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• frovatriptan

  Monitor Closely (1)frovatriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• ganaxolone

  Monitor Closely (1)trifluoperazine and ganaxolone both increase sedation. Use Caution/Monitor.

• gemifloxacin

  Monitor Closely (1)gemifloxacin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• gilteritinib

  Monitor Closely (1)gilteritinib and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• givosiran

  Serious - Use Alternative (1)givosiran will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.

• glycopyrrolate

  Monitor Closely (1)trifluoperazine increases effects of glycopyrrolate by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)trifluoperazine increases toxicity of glycopyrrolate by unknown mechanism. Minor/Significance Unknown.

• glycopyrrolate inhaled

  Monitor Closely (3)glycopyrrolate inhaled decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  glycopyrrolate inhaled decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of glycopyrrolate inhaled by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)trifluoperazine increases toxicity of glycopyrrolate inhaled by unknown mechanism. Minor/Significance Unknown.

• glycopyrronium tosylate topical

  Monitor Closely (1)glycopyrronium tosylate topical, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration of glycopyrronium tosylate topical with other anticholinergic medications may result in additive anticholinergic adverse effects.

• granisetron

  Monitor Closely (1)granisetron and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• guanfacine

  Monitor Closely (1)guanfacine, trifluoperazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Additive hypotensive effects; potential delirium.

• haloperidol

  Monitor Closely (2)haloperidol and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  haloperidol and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and haloperidol both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)haloperidol will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• henbane

  Monitor Closely (3)henbane decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  henbane decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of henbane by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• homatropine

  Monitor Closely (3)homatropine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  homatropine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of homatropine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hydrocodone

  Serious - Use Alternative (1)hydrocodone, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• hydromorphone

  Monitor Closely (1)hydromorphone and trifluoperazine both increase sedation. Use Caution/Monitor.

• hydroxyzine

  Monitor Closely (2)hydroxyzine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  hydroxyzine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• hyoscyamine

  Monitor Closely (3)hyoscyamine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of hyoscyamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• hyoscyamine spray

  Monitor Closely (3)trifluoperazine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  hyoscyamine spray decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  hyoscyamine spray decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.

• ibutilide

  Contraindicated (1)trifluoperazine and ibutilide both increase QTc interval. Contraindicated.

• iloperidone

  Monitor Closely (3)trifluoperazine and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  iloperidone and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  iloperidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• imatinib

  Minor (1)imatinib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• imidapril

  Minor (1)trifluoperazine increases effects of imidapril by unspecified interaction mechanism. Minor/Significance Unknown.

• imipramine

  Monitor Closely (1)trifluoperazine and imipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and imipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)imipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  imipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• incobotulinumtoxinA

  Monitor Closely (1)trifluoperazine increases effects of incobotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• indacaterol, inhaled

  Monitor Closely (1)indacaterol, inhaled, trifluoperazine. QTc interval. Use Caution/Monitor. Drugs that are known to prolong the QTc interval may have an increased the risk of ventricular arrhythmias.

• indapamide

  Contraindicated (1)trifluoperazine and indapamide both increase QTc interval. Contraindicated.

• insulin degludec

  Monitor Closely (1)trifluoperazine decreases effects of insulin degludec by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin degludec/insulin aspart

  Monitor Closely (1)trifluoperazine decreases effects of insulin degludec/insulin aspart by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• insulin inhaled

  Monitor Closely (1)trifluoperazine decreases effects of insulin inhaled by Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase blood glucose concentrations.

• ipratropium

  Monitor Closely (3)ipratropium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  ipratropium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of ipratropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• isoflurane

  Monitor Closely (1)isoflurane and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• isoproterenol

  Monitor Closely (2)trifluoperazine, isoproterenol. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and isoproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• itraconazole

  Serious - Use Alternative (1)trifluoperazine and itraconazole both increase QTc interval. Avoid or Use Alternate Drug.

• ketamine

  Monitor Closely (1)ketamine and trifluoperazine both increase sedation. Use Caution/Monitor.

• ketoconazole

  Serious - Use Alternative (1)trifluoperazine and ketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• ketotifen, ophthalmic

  Monitor Closely (1)trifluoperazine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.

• lapatinib

  Monitor Closely (1)trifluoperazine and lapatinib both increase QTc interval. Modify Therapy/Monitor Closely.

• lasmiditan

  Monitor Closely (1)lasmiditan, trifluoperazine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.

• lemborexant

  Monitor Closely (1)lemborexant, trifluoperazine. Either increases effects of the other by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

• levalbuterol

  Monitor Closely (1)trifluoperazine increases and levalbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• levodopa

  Serious - Use Alternative (1)trifluoperazine decreases effects of levodopa by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

• levodopa inhaled

  Serious - Use Alternative (1)trifluoperazine decreases effects of levodopa inhaled by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Phenothiazine/1st generation antipsychotics inhibit dopamine D2 receptors in varying degrees.

• levofloxacin

  Monitor Closely (1)trifluoperazine and levofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• levoketoconazole

  Serious - Use Alternative (1)trifluoperazine and levoketoconazole both increase QTc interval. Avoid or Use Alternate Drug.

• levomilnacipran

  Monitor Closely (1)levomilnacipran, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• levorphanol

  Monitor Closely (1)levorphanol and trifluoperazine both increase sedation. Use Caution/Monitor.

• linezolid

  Monitor Closely (1)linezolid, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• liraglutide

  Monitor Closely (1)trifluoperazine, liraglutide. Other (see comment). Use Caution/Monitor. Comment: Phenothiazines may increase or decrease glucose levels, monitor therapy closely when these agents are concurrently administered.

• lisdexamfetamine

  Monitor Closely (2)trifluoperazine, lisdexamfetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• lisinopril

  Minor (1)trifluoperazine increases effects of lisinopril by unspecified interaction mechanism. Minor/Significance Unknown.

• lisuride

  Serious - Use Alternative (1)trifluoperazine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.

• lithium

  Monitor Closely (3)lithium, trifluoperazine. Other (see comment). Use Caution/Monitor. Comment: Risk of neurotoxicity. Multiple mechanisms involved.
  
  lithium, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  lithium and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• lofepramine

  Monitor Closely (1)trifluoperazine and lofepramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and lofepramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)lofepramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  lofepramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• lofexidine

  Monitor Closely (1)trifluoperazine and lofexidine both increase sedation. Use Caution/Monitor.

• loprazolam

  Monitor Closely (1)loprazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• lorazepam

  Monitor Closely (1)lorazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• lorcaserin

  Monitor Closely (1)lorcaserin, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• lormetazepam

  Monitor Closely (1)lormetazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• loxapine

  Monitor Closely (2)loxapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• loxapine inhaled

  Monitor Closely (2)loxapine inhaled and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  loxapine inhaled and trifluoperazine both increase sedation. Use Caution/Monitor.

• lumefantrine

  Monitor Closely (1)lumefantrine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and lumefantrine both increase QTc interval. Avoid or Use Alternate Drug.

• lurasidone

  Monitor Closely (1)lurasidone, trifluoperazine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.

• maprotiline

  Monitor Closely (1)trifluoperazine and maprotiline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and maprotiline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)maprotiline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  maprotiline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• maraviroc

  Minor (1)maraviroc will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• marijuana

  Monitor Closely (1)trifluoperazine and marijuana both increase sedation. Use Caution/Monitor.Minor (1)marijuana will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• meclizine

  Monitor Closely (3)meclizine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  meclizine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of meclizine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• melatonin

  Monitor Closely (1)trifluoperazine and melatonin both increase sedation. Use Caution/Monitor.

• meperidine

  Monitor Closely (2)meperidine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  meperidine and trifluoperazine both increase sedation. Use Caution/Monitor.

• meprobamate

  Monitor Closely (1)trifluoperazine and meprobamate both increase sedation. Use Caution/Monitor.

• metaproterenol

  Monitor Closely (1)trifluoperazine increases and metaproterenol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• metaxalone

  Monitor Closely (1)metaxalone and trifluoperazine both increase sedation. Use Caution/Monitor.

• metformin

  Monitor Closely (1)trifluoperazine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.

• methadone

  Monitor Closely (3)methadone, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  trifluoperazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  methadone and trifluoperazine both increase sedation. Use Caution/Monitor.

• methamphetamine

  Monitor Closely (2)trifluoperazine, methamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and methamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methocarbamol

  Monitor Closely (1)methocarbamol and trifluoperazine both increase sedation. Use Caution/Monitor.

• methoxsalen

  Monitor Closely (1)methoxsalen, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Additive photosensitizing effects.

• methscopolamine

  Monitor Closely (3)methscopolamine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  methscopolamine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of methscopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• methyl aminolevulinate

  Serious - Use Alternative (1)trifluoperazine, methyl aminolevulinate. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Each drug may increase the photosensitizing effect of the other.

• methyldopa

  Serious - Use Alternative (1)trifluoperazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.

• methylenedioxymethamphetamine

  Monitor Closely (2)trifluoperazine, methylenedioxymethamphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• methylergonovine

  Monitor Closely (1)methylergonovine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• methylphenidate

  Monitor Closely (2)trifluoperazine, methylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases toxicity of methylphenidate by pharmacodynamic antagonism. Use Caution/Monitor. Closely monitor for signs of altered clinical response to either methylphenidate or an antipsychotic when using these drugs in combination.

• metoclopramide

  Monitor Closely (1)trifluoperazine and metoclopramide both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.

• metoclopramide intranasal

  Serious - Use Alternative (2)trifluoperazine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
  
  trifluoperazine increases toxicity of metoclopramide intranasal by pharmacodynamic synergism. Avoid or Use Alternate Drug. Potential for additive effects, including increased frequency and severity of tardive dyskinesia, other extrapyramidal symptoms, and neuroleptic malignant syndrome.

• metrizamide

  Contraindicated (1)trifluoperazine, metrizamide. Mechanism: unknown. Contraindicated. Risk of seizure. D/C phenothiazine 24h before admin. of metrizamide.

• metyrapone

  Minor (1)trifluoperazine decreases effects of metyrapone by unspecified interaction mechanism. Minor/Significance Unknown.

• metyrosine

  Minor (1)metyrosine increases toxicity of trifluoperazine by pharmacodynamic synergism. Minor/Significance Unknown. Increased extrapyramidal symptoms.

• midazolam

  Monitor Closely (1)midazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• midazolam intranasal

  Monitor Closely (1)midazolam intranasal, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.

• midodrine

  Monitor Closely (2)trifluoperazine, midodrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and midodrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• milnacipran

  Monitor Closely (1)milnacipran, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• mirtazapine

  Monitor Closely (2)trifluoperazine and mirtazapine both increase sedation. Use Caution/Monitor.
  
  mirtazapine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• modafinil

  Monitor Closely (1)trifluoperazine increases and modafinil decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• moexipril

  Minor (1)trifluoperazine increases effects of moexipril by unspecified interaction mechanism. Minor/Significance Unknown.

• morphine

  Monitor Closely (1)morphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• motherwort

  Monitor Closely (1)trifluoperazine and motherwort both increase sedation. Use Caution/Monitor.

• moxifloxacin

  Serious - Use Alternative (1)trifluoperazine and moxifloxacin both increase QTc interval. Avoid or Use Alternate Drug.

• moxonidine

  Monitor Closely (1)trifluoperazine and moxonidine both increase sedation. Use Caution/Monitor.

• nabilone

  Monitor Closely (1)trifluoperazine and nabilone both increase sedation. Use Caution/Monitor.

• nalbuphine

  Monitor Closely (1)nalbuphine and trifluoperazine both increase sedation. Use Caution/Monitor.

• naratriptan

  Monitor Closely (1)naratriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• nilotinib

  Serious - Use Alternative (1)trifluoperazine and nilotinib both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)nilotinib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• norepinephrine

  Monitor Closely (2)trifluoperazine, norepinephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and norepinephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• nortriptyline

  Monitor Closely (1)trifluoperazine and nortriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and nortriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)nortriptyline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  nortriptyline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• octreotide

  Serious - Use Alternative (1)trifluoperazine and octreotide both increase QTc interval. Avoid or Use Alternate Drug.

• octreotide (Antidote)

  Serious - Use Alternative (1)trifluoperazine and octreotide (Antidote) both increase QTc interval. Avoid or Use Alternate Drug.

• ofloxacin

  Monitor Closely (1)trifluoperazine and ofloxacin both increase QTc interval. Modify Therapy/Monitor Closely.

• olanzapine

  Monitor Closely (3)olanzapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  olanzapine and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  olanzapine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• oliceridine

  Monitor Closely (1)oliceridine, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation. Increased risk of hypotension if ability to maintain blood pressure has been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (eg, phenothiazines or general anesthetics).

• olodaterol inhaled

  Monitor Closely (1)trifluoperazine and olodaterol inhaled both increase QTc interval. Use Caution/Monitor. Drugs that prolong the QTc interval and may potentiate the effects of beta2 agonists on the cardiovascular system; increased risk of ventricular arrhythmias

• onabotulinumtoxinA

  Monitor Closely (3)onabotulinumtoxinA decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  onabotulinumtoxinA decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of onabotulinumtoxinA by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• opium tincture

  Monitor Closely (1)opium tincture and trifluoperazine both increase sedation. Use Caution/Monitor.

• orphenadrine

  Monitor Closely (1)orphenadrine and trifluoperazine both increase sedation. Use Caution/Monitor.

• oxaliplatin

  Monitor Closely (1)oxaliplatin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• oxazepam

  Monitor Closely (1)oxazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• oxybutynin

  Monitor Closely (3)oxybutynin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of oxybutynin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin increases toxicity of trifluoperazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin topical

  Monitor Closely (3)oxybutynin topical decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin topical decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin topical increases toxicity of trifluoperazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxybutynin transdermal

  Monitor Closely (3)oxybutynin transdermal decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  oxybutynin transdermal decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.Minor (1)oxybutynin transdermal increases toxicity of trifluoperazine by unspecified interaction mechanism. Minor/Significance Unknown.

• oxycodone

  Monitor Closely (1)oxycodone and trifluoperazine both increase sedation. Use Caution/Monitor.

• oxymorphone

  Monitor Closely (1)oxymorphone and trifluoperazine both increase sedation. Use Caution/Monitor.

• paliperidone

  Monitor Closely (3)trifluoperazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  paliperidone and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  paliperidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• pancuronium

  Monitor Closely (3)pancuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pancuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of pancuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• papaveretum

  Monitor Closely (1)papaveretum and trifluoperazine both increase sedation. Use Caution/Monitor.

• papaverine

  Monitor Closely (1)trifluoperazine and papaverine both increase sedation. Use Caution/Monitor.

• parecoxib

  Minor (1)parecoxib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• paroxetine

  Monitor Closely (3)paroxetine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  trifluoperazine and paroxetine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  paroxetine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• pazopanib

  Monitor Closely (1)trifluoperazine and pazopanib both increase QTc interval. Use Caution/Monitor.

• pentamidine

  Contraindicated (1)trifluoperazine and pentamidine both increase QTc interval. Contraindicated.

• pentazocine

  Monitor Closely (1)pentazocine and trifluoperazine both increase sedation. Use Caution/Monitor.

• pentobarbital

  Monitor Closely (1)pentobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• perindopril

  Minor (1)trifluoperazine increases effects of perindopril by unspecified interaction mechanism. Minor/Significance Unknown.

• perphenazine

  Monitor Closely (2)perphenazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  perphenazine and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)perphenazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)perphenazine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• phendimetrazine

  Monitor Closely (2)trifluoperazine, phendimetrazine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and phendimetrazine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenelzine

  Monitor Closely (1)phenelzine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• phenobarbital

  Monitor Closely (1)phenobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• phentermine

  Monitor Closely (2)trifluoperazine, phentermine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and phentermine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine

  Monitor Closely (2)trifluoperazine, phenylephrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and phenylephrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• phenylephrine PO

  Monitor Closely (2)trifluoperazine, phenylephrine PO. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

• pholcodine

  Monitor Closely (1)trifluoperazine and pholcodine both increase sedation. Use Caution/Monitor.

• pimozide

  Contraindicated (1)trifluoperazine and pimozide both increase QTc interval. Contraindicated.Monitor Closely (2)pimozide and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  pimozide and trifluoperazine both increase sedation. Use Caution/Monitor.

• pirbuterol

  Monitor Closely (1)trifluoperazine increases and pirbuterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• porfimer

  Monitor Closely (1)trifluoperazine, porfimer. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Enhanced photosensitivity.

• posaconazole

  Monitor Closely (1)trifluoperazine and posaconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• pralidoxime

  Monitor Closely (3)pralidoxime decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  pralidoxime decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of pralidoxime by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• pramipexole

  Serious - Use Alternative (1)trifluoperazine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.

• primaquine

  Monitor Closely (1)primaquine and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• primidone

  Monitor Closely (1)primidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• procainamide

  Contraindicated (1)trifluoperazine and procainamide both increase QTc interval. Contraindicated.

• procarbazine

  Monitor Closely (2)procarbazine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  procarbazine, trifluoperazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Excessive sedation.

• prochlorperazine

  Monitor Closely (2)prochlorperazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  prochlorperazine and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)prochlorperazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• promazine

  Serious - Use Alternative (1)promazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• promethazine

  Monitor Closely (3)promethazine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  promethazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  promethazine and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)promethazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.

• propafenone

  Monitor Closely (1)propafenone will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• propantheline

  Monitor Closely (3)propantheline decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  propantheline decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of propantheline by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• propofol

  Monitor Closely (1)propofol and trifluoperazine both increase sedation. Use Caution/Monitor.

• propylhexedrine

  Monitor Closely (2)trifluoperazine, propylhexedrine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• protriptyline

  Monitor Closely (1)trifluoperazine and protriptyline both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and protriptyline both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)protriptyline, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  protriptyline, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• pseudoephedrine

  Monitor Closely (1)trifluoperazine, pseudoephedrine. Mechanism: unknown. Use Caution/Monitor. Consider avoiding use of pseudoephedrine in patients receiving phenothiazines (especially thioridazine) due to the potential risk of cardiac arrhythmia or sudden death. Monitor for evidence of ventricular arrhythmias during concomitant use.

• pyrimethamine

  Minor (1)pyrimethamine increases levels of trifluoperazine by decreasing metabolism. Minor/Significance Unknown.

• quazepam

  Monitor Closely (1)quazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• quetiapine

  Monitor Closely (2)quetiapine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  quetiapine and trifluoperazine both increase sedation. Use Caution/Monitor.

• quinacrine

  Minor (1)quinacrine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• quinapril

  Minor (1)trifluoperazine increases effects of quinapril by unspecified interaction mechanism. Minor/Significance Unknown.

• quinidine

  Contraindicated (1)trifluoperazine and quinidine both increase QTc interval. Contraindicated.Monitor Closely (1)quinidine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.Serious - Use Alternative (1)quinidine, trifluoperazine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive cardiac effects.

• ramelteon

  Monitor Closely (1)trifluoperazine and ramelteon both increase sedation. Use Caution/Monitor.

• ramipril

  Minor (1)trifluoperazine increases effects of ramipril by unspecified interaction mechanism. Minor/Significance Unknown.

• ranolazine

  Monitor Closely (1)trifluoperazine and ranolazine both increase QTc interval. Modify Therapy/Monitor Closely.Minor (1)ranolazine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• rapacuronium

  Monitor Closely (3)rapacuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rapacuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of rapacuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• remimazolam

  Monitor Closely (1)remimazolam, trifluoperazine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.

• rimabotulinumtoxinB

  Monitor Closely (1)trifluoperazine, rimabotulinumtoxinB. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Anticholinergics may enhance botulinum toxin effects. Closely monitor for increased neuromuscular blockade.

• risperidone

  Monitor Closely (3)trifluoperazine and risperidone both increase QTc interval. Modify Therapy/Monitor Closely.
  
  risperidone and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  risperidone and trifluoperazine both increase sedation. Use Caution/Monitor.

• ritonavir

  Minor (1)ritonavir will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• rizatriptan

  Monitor Closely (1)rizatriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• rocuronium

  Monitor Closely (3)rocuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  rocuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of rocuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• romidepsin

  Monitor Closely (1)trifluoperazine and romidepsin both increase QTc interval. Modify Therapy/Monitor Closely.

• ropinirole

  Serious - Use Alternative (1)trifluoperazine decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.

• rucaparib

  Monitor Closely (1)rucaparib will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP1A2 substrates, if clinically indicated.

• safinamide

  Serious - Use Alternative (1)trifluoperazine decreases effects of safinamide by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Dopamine antagonists may decrease safinamide effects and exacerbate Parkinson disease symptoms.

• sage

  Minor (1)trifluoperazine and sage both increase sedation. Minor/Significance Unknown.

• salmeterol

  Monitor Closely (1)trifluoperazine increases and salmeterol decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• scopolamine

  Monitor Closely (3)scopolamine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  scopolamine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of scopolamine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• scullcap

  Monitor Closely (1)trifluoperazine and scullcap both increase sedation. Use Caution/Monitor.

• secobarbital

  Monitor Closely (1)secobarbital and trifluoperazine both increase sedation. Use Caution/Monitor.

• selegiline

  Monitor Closely (1)selegiline, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• selinexor

  Serious - Use Alternative (1)selinexor, trifluoperazine. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.

• serdexmethylphenidate/dexmethylphenidate

  Monitor Closely (1)trifluoperazine, serdexmethylphenidate/dexmethylphenidate. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.

• sertraline

  Monitor Closely (1)sertraline and trifluoperazine both decrease QTc interval. Use Caution/Monitor.Minor (1)sertraline will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• sevoflurane

  Monitor Closely (2)sevoflurane and trifluoperazine both increase sedation. Use Caution/Monitor.
  
  sevoflurane and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• shepherd's purse

  Monitor Closely (1)trifluoperazine and shepherd's purse both increase sedation. Use Caution/Monitor.

• siponimod

  Monitor Closely (1)siponimod and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• smoking

  Monitor Closely (1)smoking decreases levels of trifluoperazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• sodium oxybate

  Serious - Use Alternative (1)trifluoperazine, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• sodium sulfate/?magnesium sulfate/potassium chloride

  Monitor Closely (1)sodium sulfate/?magnesium sulfate/potassium chloride increases effects of trifluoperazine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• sodium sulfate/potassium sulfate/magnesium sulfate

  Monitor Closely (1)sodium sulfate/potassium sulfate/magnesium sulfate increases effects of trifluoperazine by unknown mechanism. Use Caution/Monitor. Closely monitor for evidence of enhanced CNS depression when using higher dose of magnesium sulfate together with a CNS depressant.

• solifenacin

  Monitor Closely (4)solifenacin decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  solifenacin decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of solifenacin by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.
  
  solifenacin and trifluoperazine both decrease QTc interval. Use Caution/Monitor.

• sotalol

  Contraindicated (1)trifluoperazine and sotalol both increase QTc interval. Contraindicated.

• stiripentol

  Monitor Closely (1)stiripentol, trifluoperazine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.

• sufentanil

  Monitor Closely (1)sufentanil and trifluoperazine both increase sedation. Use Caution/Monitor.

• sufentanil SL

  Serious - Use Alternative (1)sufentanil SL, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.

• sulfamethoxazole

  Monitor Closely (1)trifluoperazine and sulfamethoxazole both increase QTc interval. Modify Therapy/Monitor Closely.

• sumatriptan

  Monitor Closely (1)sumatriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• sumatriptan intranasal

  Monitor Closely (1)sumatriptan intranasal, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• tapentadol

  Monitor Closely (1)tapentadol and trifluoperazine both increase sedation. Use Caution/Monitor.

• teduglutide

  Monitor Closely (1)teduglutide increases levels of trifluoperazine by Other (see comment). Use Caution/Monitor. Comment: Teduglutide may increase absorption of concomitant PO medications; caution with with drugs requiring titration or those with a narrow therapeutic index; dose adjustment may be necessary.

• telavancin

  Monitor Closely (1)trifluoperazine and telavancin both increase QTc interval. Modify Therapy/Monitor Closely.

• temazepam

  Monitor Closely (1)temazepam and trifluoperazine both increase sedation. Use Caution/Monitor.

• terbutaline

  Monitor Closely (1)trifluoperazine increases and terbutaline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• teriflunomide

  Monitor Closely (1)teriflunomide decreases levels of trifluoperazine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.

• tetrabenazine

  Monitor Closely (1)trifluoperazine and tetrabenazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Modify Therapy/Monitor Closely.

• thioridazine

  Monitor Closely (2)thioridazine and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  thioridazine and trifluoperazine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)thioridazine and trifluoperazine both increase QTc interval. Avoid or Use Alternate Drug.Minor (1)thioridazine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• thiothixene

  Monitor Closely (2)thiothixene and trifluoperazine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  thiothixene and trifluoperazine both increase sedation. Use Caution/Monitor.

• tiotropium

  Monitor Closely (3)tiotropium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tiotropium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of tiotropium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• tipranavir

  Minor (1)tipranavir will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.

• tobacco use

  Monitor Closely (1)tobacco use decreases levels of trifluoperazine by increasing metabolism. Use Caution/Monitor. Interaction mainly seen w/chlorpromazine & thioridazine, but may occur w/other phenothiazines.

• tolterodine

  Monitor Closely (3)tolterodine decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  tolterodine decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of tolterodine by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• topiramate

  Monitor Closely (1)trifluoperazine and topiramate both increase sedation. Modify Therapy/Monitor Closely.

• tramadol

  Monitor Closely (1)tramadol and trifluoperazine both increase sedation. Use Caution/Monitor.

• trandolapril

  Minor (1)trifluoperazine increases effects of trandolapril by unspecified interaction mechanism. Minor/Significance Unknown.

• tranylcypromine

  Monitor Closely (1)tranylcypromine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• trazodone

  Monitor Closely (1)trifluoperazine and trazodone both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and trazodone both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)trazodone, trifluoperazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.
  
  trazodone, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.

• tretinoin

  Serious - Use Alternative (1)trifluoperazine, tretinoin. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• tretinoin topical

  Serious - Use Alternative (1)trifluoperazine, tretinoin topical. Mechanism: pharmacodynamic synergism. Avoid or Use Alternate Drug. Increased phototoxicity.

• triazolam

  Monitor Closely (1)triazolam and trifluoperazine both increase sedation. Use Caution/Monitor.

• triclofos

  Monitor Closely (1)triclofos and trifluoperazine both increase sedation. Use Caution/Monitor.

• trihexyphenidyl

  Monitor Closely (2)trihexyphenidyl decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.

• trimethoprim

  Monitor Closely (1)trifluoperazine and trimethoprim both increase QTc interval. Modify Therapy/Monitor Closely.

• trimipramine

  Monitor Closely (1)trifluoperazine and trimipramine both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and trimipramine both increase QTc interval. Avoid or Use Alternate Drug.Minor (2)trimipramine, trifluoperazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.
  
  trimipramine, trifluoperazine. Either increases levels of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive anticholinergic effects.

• triprolidine

  Monitor Closely (1)triprolidine and trifluoperazine both increase sedation. Use Caution/Monitor.

• tropisetron

  Monitor Closely (1)trifluoperazine and tropisetron both increase QTc interval. Modify Therapy/Monitor Closely.

• trospium chloride

  Monitor Closely (3)trospium chloride decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  trospium chloride decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• vecuronium

  Monitor Closely (3)vecuronium decreases levels of trifluoperazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.
  
  vecuronium decreases levels of trifluoperazine by pharmacodynamic antagonism. Use Caution/Monitor.
  
  trifluoperazine increases effects of vecuronium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

• venlafaxine

  Monitor Closely (3)venlafaxine, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).
  
  trifluoperazine and venlafaxine both increase QTc interval. Modify Therapy/Monitor Closely.
  
  venlafaxine will increase the level or effect of trifluoperazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

• vilazodone

  Monitor Closely (1)vilazodone, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• voriconazole

  Monitor Closely (1)trifluoperazine and voriconazole both increase QTc interval. Modify Therapy/Monitor Closely.

• xylometazoline

  Monitor Closely (2)trifluoperazine, xylometazoline. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• yohimbe

  Serious - Use Alternative (1)yohimbe decreases effects of trifluoperazine by pharmacodynamic antagonism. Contraindicated.

• yohimbine

  Monitor Closely (2)trifluoperazine, yohimbine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
  
  trifluoperazine increases and yohimbine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

• ziconotide

  Monitor Closely (1)trifluoperazine and ziconotide both increase sedation. Use Caution/Monitor.

• ziprasidone

  Monitor Closely (2)trifluoperazine and ziprasidone both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  trifluoperazine and ziprasidone both increase sedation. Use Caution/Monitor.Serious - Use Alternative (1)trifluoperazine and ziprasidone both increase QTc interval. Avoid or Use Alternate Drug.

• zolmitriptan

  Monitor Closely (1)zolmitriptan, trifluoperazine. unspecified interaction mechanism. Use Caution/Monitor. Serotonin modulators may enhance dopamine blockade, possibly increasing the risk for neuroleptic malignant syndrome. Antipsychotics may enhance serotonergic effect of serotonin modulators, which may result in serotonin syndrome. Monitor for evidence of serotonin toxicity (eg, mental status changes, autonomic instability, and neuromuscular hyperactivity) or neuroleptic malignant syndrome (eg, hyperthermia, muscle rigidity, autonomic dysfunction).

• zolpidem

  Monitor Closely (1)trifluoperazine will increase the level or effect of zolpidem by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Additive effect of decreased alertness and psychomotor performance

• zotepine

  Monitor Closely (2)trifluoperazine and zotepine both increase antidopaminergic effects, including extrapyramidal symptoms and neuroleptic malignant syndrome. Use Caution/Monitor.
  
  trifluoperazine and zotepine both increase sedation. Use Caution/Monitor.