thioridazine (Rx)

Brand and Other Names:Mellaril
  • Print

Dosing & Uses

AdultPediatricGeriatric

Dosage Forms & Strengths

tablet

  • 10mg
  • 25mg
  • 50mg
  • 100mg

Schizophrenia

Initial 50-100 mg PO q8hr, THEN

200-800 mg/day PO divided q6-12hr

Depressive Disorders

25 mg PO q8hr; may titrate to effect (20-200 mg/day)

Renal Impairment

Dose adjustment not necessary in dialysis

Hepatic Disease

Initiate treatment at lower dose and titrate to effect (monitor)

Other Indications & Uses

Psychotic disorders, geriatric psychoneurotic manifestations, pediatric behavioral disorders

Dosage Forms & Strengths

tablet

  • 10mg
  • 25mg
  • 50mg
  • 100mg

Schizophrenia

<2 years: Safety and efficacy not established

2-12 years: 0.5-3 mg/kg/day divided q8hr PO, no more than 3 mg/kg/day  

>12 years: Initial 50-100 mg PO q8hr; titrate to 200-800 mg/day PO divided q6-12hr

Potential toxic dose <6 years old: 3 mg/kg

Initiate treatment at lower dose and titrate to effect (monitor)

Schizophrenia

Initial 50-100 mg PO q8hr, THEN

200-800 mg/day PO divided q6-12hr

Debilitated patients: Initiate treatment at lower dose

Depressive disorders

25 mg PO q8hr; may titrate to effect (20-200 mg/day)

Next:

Interactions

Interaction Checker

and thioridazine

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

            All Interactions Sort By:
             activity indicator 

            Contraindicated (38)

            • albuterol

              albuterol and thioridazine both increase QTc interval. Contraindicated.

            • alfuzosin

              alfuzosin and thioridazine both increase QTc interval. Contraindicated.

            • amiodarone

              thioridazine and amiodarone both increase QTc interval. Contraindicated.

            • apomorphine

              apomorphine and thioridazine both increase QTc interval. Contraindicated.

            • arformoterol

              arformoterol and thioridazine both increase QTc interval. Contraindicated.

            • aripiprazole

              aripiprazole and thioridazine both increase QTc interval. Contraindicated.

            • artemether

              artemether and thioridazine both increase QTc interval. Contraindicated.

            • atomoxetine

              atomoxetine and thioridazine both increase QTc interval. Contraindicated.

            • ceritinib

              ceritinib and thioridazine both increase QTc interval. Contraindicated.

            • clomipramine

              thioridazine will increase the level or effect of clomipramine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • crizotinib

              crizotinib and thioridazine both increase QTc interval. Contraindicated. Thioridazine is contraindicated with drugs that may prolong the QT interval.

            • desipramine

              thioridazine will increase the level or effect of desipramine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • disopyramide

              thioridazine and disopyramide both increase QTc interval. Contraindicated.

            • dofetilide

              dofetilide increases toxicity of thioridazine by QTc interval. Contraindicated.

            • doxepin

              thioridazine will increase the level or effect of doxepin by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • eliglustat

              thioridazine increases levels of eliglustat by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. If coadministered with strong or moderate CYP2D6 inhibitors, reduce eliglustat dose from 84 mg BID to 84 mg once daily in extensive and intermediate metabolizers; eliglustat is contraindiated if strong or moderate CYP2D6 inhibitors are given concomitantly with strong or moderate CYP3A inhibitors.

            • escitalopram

              escitalopram increases toxicity of thioridazine by QTc interval. Contraindicated.

            • fluoxetine

              thioridazine will increase the level or effect of fluoxetine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

              thioridazine and fluoxetine both increase QTc interval. Contraindicated.

              fluoxetine increases levels of thioridazine by decreasing metabolism. Contraindicated. Risk of long QT syndrome.

            • goserelin

              goserelin increases toxicity of thioridazine by QTc interval. Contraindicated. Increases risk of torsades de pointes.

            • ibutilide

              thioridazine and ibutilide both increase QTc interval. Contraindicated.

            • imipramine

              thioridazine will increase the level or effect of imipramine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • indapamide

              thioridazine and indapamide both increase QTc interval. Contraindicated.

            • leuprolide

              leuprolide increases toxicity of thioridazine by QTc interval. Contraindicated. Increases risk of torsades de pointes.

            • metrizamide

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

            • mifepristone

              mifepristone, thioridazine. QTc interval. Contraindicated.

            • nortriptyline

              thioridazine will increase the level or effect of nortriptyline by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • paroxetine

              paroxetine increases levels of thioridazine by decreasing metabolism. Contraindicated. Risk of long QT syndrome.

            • pasireotide

              thioridazine and pasireotide both increase QTc interval. Contraindicated.

            • pentamidine

              thioridazine and pentamidine both increase QTc interval. Contraindicated.

            • pimozide

              thioridazine and pimozide both increase QTc interval. Contraindicated.

            • procainamide

              thioridazine and procainamide both increase QTc interval. Contraindicated.

            • quinidine

              thioridazine and quinidine both increase QTc interval. Contraindicated.

            • quinine

              thioridazine and quinine both increase QTc interval. Contraindicated.

            • rolapitant

              rolapitant will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated. Rolapitant moderately inhibits CYP2D6. Coadministration with thioridazine, a CYP2D6 substrate, causes a significant increase in thioridazine plasma concentration that may result in QT prolongation and torsades de pointes.

            • sertraline

              sertraline increases levels of thioridazine by decreasing metabolism. Contraindicated. Risk of long QT syndrome.

            • sorafenib

              sorafenib and thioridazine both increase QTc interval. Contraindicated.

            • sotalol

              thioridazine and sotalol both increase QTc interval. Contraindicated.

            • toremifene

              thioridazine and toremifene both increase QTc interval. Contraindicated. Concurrent use of thioridazine with other agents that prolong QTc interval is contraindicated.

            Serious - Use Alternative (123)

            • aminolevulinic acid oral

              aminolevulinic acid oral, thioridazine. 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

              thioridazine 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

              amiodarone will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

              amiodarone increases levels of thioridazine by decreasing metabolism. Contraindicated.

            • amitriptyline

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

            • amoxapine

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

            • apomorphine

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

            • arsenic trioxide

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

            • artemether/lumefantrine

              artemether/lumefantrine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

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

            • asenapine

              asenapine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • benzhydrocodone/acetaminophen

              benzhydrocodone/acetaminophen, thioridazine. 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).

            • bremelanotide

              bremelanotide will decrease the level or effect of thioridazine by Other (see comment). Avoid or Use Alternate Drug. Bremelanotide may slow gastric emptying and potentially reduces the rate and extent of absorption of concomitantly administered oral medications. Avoid use when taking any oral drug that is dependent on threshold concentrations for efficacy. Interactions listed are representative examples and do not include all possible clinical examples.

            • bromocriptine

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

            • bupropion

              bupropion will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • cabergoline

              thioridazine decreases effects of cabergoline by pharmacodynamic antagonism. Contraindicated.

            • calcium/magnesium/potassium/sodium oxybates

              thioridazine, 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.

            • carvedilol

              carvedilol, thioridazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

            • celecoxib

              celecoxib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • chloroquine

              chloroquine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • chlorpromazine

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

            • cimetidine

              cimetidine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • citalopram

              thioridazine and citalopram both increase QTc interval. Avoid or Use Alternate Drug. Thioridazine should be avoided in combination with drugs that are known to prolong QTc interval.

            • clarithromycin

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

            • clomipramine

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

            • dacomitinib

              dacomitinib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid use with CYP2D6 substrates where minimal increases in concentration of the CYP2D6 substrate may lead to serious or life-threatening toxicities.

            • darifenacin

              darifenacin will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • desipramine

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

            • diphenhydramine

              diphenhydramine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • dofetilide

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

            • dopamine

              thioridazine decreases effects of dopamine by pharmacodynamic antagonism. Contraindicated.

            • dosulepin

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

            • doxepin

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

            • dronedarone

              dronedarone will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

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

            • droperidol

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

            • duloxetine

              duloxetine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

              thioridazine will increase the level or effect of duloxetine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • encorafenib

              encorafenib and thioridazine both increase QTc interval. Avoid or Use Alternate Drug. Encorafenib is associated with dose-dependent QTc interval prolongation. Avoid with drugs known to prolong QT interval.

            • entrectinib

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

            • epinephrine

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

            • epinephrine racemic

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

            • eribulin

              eribulin and thioridazine both increase QTc interval. Avoid or Use Alternate Drug. Potential for enhanced QTc-prolonging effects; if concurrent use is necessary then ECG monitoring is recommended.

            • erythromycin base

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

            • erythromycin ethylsuccinate

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

            • erythromycin lactobionate

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

            • erythromycin stearate

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

            • fentanyl

              fentanyl, thioridazine. 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, thioridazine. 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, thioridazine. 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, thioridazine. 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.

            • fexinidazole

              fexinidazole and thioridazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of fexinidazole with drugs known to block potassium channels and/or prolong QT interval.

            • fluconazole

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

            • fluoxetine

              fluoxetine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • fluphenazine

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

            • fluvoxamine

              fluvoxamine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated.

              fluvoxamine and thioridazine both increase QTc interval. Contraindicated.

            • formoterol

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

            • givosiran

              givosiran will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP2D6 substrates with givosiran. If unavoidable, decrease the CYP2D6 substrate dosage in accordance with approved product labeling.

            • glasdegib

              thioridazine and glasdegib both increase QTc interval. Avoid or Use Alternate Drug. If coadministration unavoidable, monitor for increased risk of QTc interval prolongation.

            • haloperidol

              haloperidol will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

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

            • histrelin

              histrelin increases toxicity of thioridazine by QTc interval. Avoid or Use Alternate Drug. Increases risk of torsades de pointes.

            • hydrocodone

              hydrocodone, thioridazine. 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).

            • hydroxychloroquine sulfate

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

            • imatinib

              imatinib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • imipramine

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

            • inotuzumab

              inotuzumab and thioridazine both increase QTc interval. Avoid or Use Alternate Drug. If unable to avoid concomitant use, obtain ECGs and electrolytes before and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.

            • itraconazole

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

            • ivosidenib

              ivosidenib and thioridazine both increase QTc interval. Avoid or Use Alternate Drug. Avoid coadministration of QTc prolonging drugs with ivosidenib or replace with alternate therapies. If coadministration of a QTc prolonging drug is unavoidable, monitor for increased risk of QTc interval prolongation.

            • ketoconazole

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

            • lefamulin

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

            • levodopa

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

            • levodopa inhaled

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

            • lisuride

              thioridazine decreases effects of lisuride by pharmacodynamic antagonism. Contraindicated.

            • lofepramine

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

            • lumefantrine

              lumefantrine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

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

            • macimorelin

              macimorelin and thioridazine both increase QTc interval. Avoid or Use Alternate Drug. Macimorelin causes an increase of ~11 msec in the corrected QT interval. Avoid coadministration with drugs that prolong QT interval, which could increase risk for developing torsade de pointes-type ventricular tachycardia. Allow sufficient washout time of drugs that are known to prolong the QT interval before administering macimorelin.

            • maprotiline

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

            • maraviroc

              maraviroc will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • marijuana

              marijuana will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • mefloquine

              mefloquine increases toxicity of thioridazine by QTc interval. Avoid or Use Alternate Drug. Mefloquine may enhance the QTc prolonging effect of high risk QTc prolonging agents.

            • methyl aminolevulinate

              thioridazine, 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

              thioridazine decreases effects of methyldopa by pharmacodynamic antagonism. Contraindicated.

            • metoclopramide intranasal

              thioridazine will increase the level or effect of metoclopramide intranasal by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Concurrent use of metoclopramide intranasal and strong CYP2D6 inhibitors is not recommended since the metoclopramide intranasal dose cannot be adjusted.

              thioridazine, 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.

              thioridazine 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.

            • metoprolol

              metoprolol, thioridazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

            • moxifloxacin

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

            • nilotinib

              nilotinib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

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

            • nortriptyline

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

            • octreotide

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

            • octreotide (Antidote)

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

            • ondansetron

              thioridazine and ondansetron both increase QTc interval. Avoid or Use Alternate Drug. Avoid with congenital long QT syndrome; ECG monitoring recommended with concomitant medications that prolong QT interval, electrolyte abnormalities, CHF, or bradyarrhythmias.

            • panobinostat

              thioridazine and panobinostat both increase QTc interval. Avoid or Use Alternate Drug. Panobinostat is known to significantly prolong QT interval. Panobinostat prescribing information states use with drugs known to prolong QTc is not recommended.

            • parecoxib

              parecoxib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • paroxetine

              paroxetine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

              thioridazine will increase the level or effect of paroxetine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

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

            • perphenazine

              perphenazine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

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

            • pimavanserin

              pimavanserin and thioridazine both increase QTc interval. Avoid or Use Alternate Drug. Coadministration may increase the risk of QT prolongation and cardiac arrhythmia.

            • pitolisant

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

            • pramipexole

              thioridazine decreases effects of pramipexole by pharmacodynamic antagonism. Contraindicated.

            • prochlorperazine

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

            • promazine

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

            • promethazine

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

            • propafenone

              propafenone will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. The concurrent administration of thioridazine and agents that prolong the QT interval, such as Class I antiarrhythmic agents, is contraindicated.

              thioridazine will increase the level or effect of propafenone by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. The concurrent administration of thioridazine and agents that prolong the QT interval, such as Class I antiarrhythmic agents, is contraindicated.

            • propranolol

              thioridazine will increase the level or effect of propranolol by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Due to the potential for significant, possibly life-threatening, proarrhythmic effects, concurrent administration of thioridazine and propranolol is contraindicated.

              propranolol, thioridazine. Either increases levels of the other by decreasing metabolism. Contraindicated. Not all beta blockers share this interaction (e.g., atenolol, nadolol, sotalol do not interact).

            • protriptyline

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

            • quinacrine

              quinacrine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • quinidine

              quinidine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

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

            • ranolazine

              ranolazine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • ribociclib

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

            • ritonavir

              ritonavir will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • ropinirole

              thioridazine decreases effects of ropinirole by pharmacodynamic antagonism. Contraindicated.

            • safinamide

              thioridazine 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, thioridazine. 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.

            • sertraline

              sertraline will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Contraindicated.

            • sodium oxybate

              thioridazine, 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.

            • tipranavir

              tipranavir will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

            • trazodone

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

            • tretinoin

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

            • tretinoin topical

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

            • trifluoperazine

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

            • trimipramine

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

            • triptorelin

              triptorelin increases toxicity of thioridazine by QTc interval. Avoid or Use Alternate Drug. Increases risk of torsades de pointes.

            • umeclidinium bromide/vilanterol inhaled

              thioridazine increases toxicity of umeclidinium bromide/vilanterol inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

            • vandetanib

              thioridazine, vandetanib. Either increases toxicity of the other by QTc interval. Avoid or Use Alternate Drug. Avoid coadministration with drugs known to prolong QT interval; if a drug known to prolong QT interval must be used, more frequent ECG monitoring is recommended.

            • vemurafenib

              vemurafenib increases levels of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug. Concomitant use of vemurafenib with agents with narrow therapeutic windows is not recommended as vemurafenib may alter their concentrations. If coadministration cannot be avoided, use caution and consider dose reduction of concomitant CYP2D6 substrate drug. Combination may increase risk QT prolongation.

            • venlafaxine

              venlafaxine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.

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

            • vilanterol/fluticasone furoate inhaled

              thioridazine increases toxicity of vilanterol/fluticasone furoate inhaled by QTc interval. Avoid or Use Alternate Drug. Exercise extreme caution when vilanterol coadministered with drugs that prolong QTc interval; adrenergic agonist effects on the cardiovascular system may be potentiated.

            • yohimbe

              yohimbe decreases effects of thioridazine by pharmacodynamic antagonism. Contraindicated.

            • ziprasidone

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

            Monitor Closely (303)

            • abiraterone

              abiraterone increases levels of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.

            • abobotulinumtoxinA

              abobotulinumtoxinA increases effects of thioridazine 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 thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • albiglutide

              thioridazine, 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

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

            • alfentanil

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

            • alfuzosin

              thioridazine and alfuzosin both increase QTc interval. Use Caution/Monitor.

            • alprazolam

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

            • amifampridine

              thioridazine 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.

            • amitriptyline

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

            • amobarbital

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

            • amoxapine

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

              thioridazine and amoxapine both increase sedation. Use Caution/Monitor.

            • anticholinergic/sedative combos

              anticholinergic/sedative combos decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              anticholinergic/sedative combos decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

              thioridazine increases effects of anticholinergic/sedative combos by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

            • arformoterol

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

            • aripiprazole

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

              aripiprazole and thioridazine both increase sedation. Use Caution/Monitor.

            • armodafinil

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

            • atomoxetine

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

            • atracurium

              atracurium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              atracurium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • atropine

              atropine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              atropine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • atropine IV/IM

              thioridazine increases effects of atropine IV/IM by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

              atropine IV/IM decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              atropine IV/IM decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

            • azelastine

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

            • azithromycin

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

            • baclofen

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

            • bedaquiline

              thioridazine and bedaquiline both increase QTc interval. Modify Therapy/Monitor Closely. ECG should be monitored closely

            • belladonna alkaloids

              belladonna alkaloids decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              belladonna alkaloids decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

              thioridazine increases effects of belladonna alkaloids by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

            • belladonna and opium

              belladonna and opium and thioridazine both increase sedation. Use Caution/Monitor.

              belladonna and opium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              belladonna and opium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

              thioridazine increases effects of belladonna and opium by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

            • benperidol

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

              benperidol and thioridazine both increase sedation. Use Caution/Monitor.

            • benzhydrocodone/acetaminophen

              thioridazine will increase the level or effect of benzhydrocodone/acetaminophen by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone [benzhydrocodone is prodrug of hydrocodone]) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.

            • benzphetamine

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

              thioridazine, 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

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

            • berotralstat

              berotralstat will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Monitor or titrate substrate dose when berotralstat is coadministered with narrow therapeutic index drugs that are CYP2D6 substrates.

            • brexanolone

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

            • brexpiprazole

              thioridazine will increase the level or effect of brexpiprazole by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Administer a quarter of brexpiprazole dose if coadministered with a moderate CYP2D6 inhibitor PLUS a strong/moderate CYP3A4 inhibitor.

            • brompheniramine

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

            • buprenorphine

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

            • buprenorphine buccal

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

            • buprenorphine, long-acting injection

              thioridazine 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.

            • butabarbital

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

            • butalbital

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

            • butorphanol

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

            • caffeine

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

            • carbinoxamine

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

            • carisoprodol

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

            • carvedilol

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

            • cenobamate

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

            • chloral hydrate

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

            • chlordiazepoxide

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

            • chloroquine

              chloroquine increases toxicity of thioridazine by QTc interval. Use Caution/Monitor.

            • chlorpheniramine

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

            • chlorpromazine

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

              chlorpromazine and thioridazine both increase sedation. Use Caution/Monitor.

            • chlorzoxazone

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

            • cigarette smoking

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

            • cinnarizine

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

            • ciprofloxacin

              ciprofloxacin and thioridazine both increase QTc interval. Use Caution/Monitor. Ciprofloxacin elicits minimal effects on QT interval. Caution if used in combination with other drugs known to affect QT interval or in patients with other risk factors.

            • cisatracurium

              cisatracurium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              cisatracurium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • clemastine

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

            • clobazam

              clobazam will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly.

              thioridazine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).

            • clomipramine

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

            • clonazepam

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

            • clonidine

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

            • clorazepate

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

            • clozapine

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

              clozapine and thioridazine both increase sedation. Use Caution/Monitor.

            • cobicistat

              cobicistat will increase the level or effect of thioridazine by Other (see comment). Modify Therapy/Monitor Closely. A decrease in the dose of antipsychotics that are metabolized by CYP3A or CYP2D6 may be needed upon coadministration.

            • codeine

              thioridazine decreases effects of codeine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Prevents conversion of codeine to its active metabolite morphine.

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

            • cyclizine

              cyclizine and thioridazine both increase sedation. Use Caution/Monitor.

              cyclizine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              cyclizine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • cyclobenzaprine

              cyclobenzaprine and thioridazine both increase sedation. Use Caution/Monitor.

              cyclobenzaprine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              cyclobenzaprine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • cyproheptadine

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

            • dantrolene

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

            • darifenacin

              darifenacin decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              darifenacin decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • dasatinib

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

            • desflurane

              desflurane and thioridazine both increase sedation. Use Caution/Monitor.

            • desipramine

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

            • desvenlafaxine

              desvenlafaxine will increase the level or effect of thioridazine 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

              thioridazine 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.

              thioridazine and deutetrabenazine both increase QTc interval. Modify Therapy/Monitor Closely. For patients requiring deutetrabenazine doses >24 mg/day and are taking other drugs known to prolong QTc, assess the QTc interval before and after increasing the dose of deutetrabenazine or other medications known to prolong QTc.

              thioridazine will increase the level or effect of deutetrabenazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Strong CYP2D6 inhibitors increase the systemic exposure to the active dihydro-metabolites of deutetrabenazine by approximately 3-fold. Do not exceed 18 mg/dose and 36 mg/day of deutetrabenazine if coadministered with strong CYP2D6 inhibitors.

            • dexchlorpheniramine

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

            • dexfenfluramine

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

              thioridazine, 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 thioridazine both increase sedation. Use Caution/Monitor.

            • dexmethylphenidate

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

              thioridazine, 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

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

              thioridazine, 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.

            • dextromoramide

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

            • diamorphine

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

            • diazepam

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

            • dicyclomine

              dicyclomine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              dicyclomine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • diethylpropion

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

              thioridazine, 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.

            • difenoxin hcl

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

            • dimenhydrinate

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

            • diphenhydramine

              diphenhydramine and thioridazine both increase sedation. Use Caution/Monitor.

              diphenhydramine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              diphenhydramine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • diphenoxylate hcl

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

            • dipipanone

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

            • dobutamine

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

              thioridazine, 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

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

            • dopamine

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

              thioridazine, 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

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

            • dosulepin

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

            • doxepin

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

            • doxylamine

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

            • droperidol

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

              droperidol and thioridazine both increase sedation. Use Caution/Monitor.

            • eliglustat

              eliglustat increases levels of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the concomitant drug and titrate to clinical effect.

            • elvitegravir/cobicistat/emtricitabine/tenofovir DF

              elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; a decrease in dose of the neuroleptic may be needed when coadministered.

            • ephedrine

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

              thioridazine, 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

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

              thioridazine, 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.

              thioridazine 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

              thioridazine increases and epinephrine racemic decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.

              thioridazine decreases effects of epinephrine racemic by pharmacodynamic antagonism. Use Caution/Monitor. Block pressor response to epinephrine, which may result in severe hypotension and tachycardia.

            • esketamine intranasal

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

            • estazolam

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

            • ethanol

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

            • ezogabine

              ezogabine, thioridazine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Slight and transient QT-prolongation observed with ezogabine, particularly when dose titrated to 1200 mg/day. QT interval should be monitored when ezogabine is prescribed with agents known to increase QT interval.

            • fedratinib

              fedratinib will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP2D6 substrates as necessary.

            • fenfluramine

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

              thioridazine, 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.

            • ferric maltol

              ferric maltol, thioridazine. Either increases levels of the other by unspecified interaction mechanism. Modify Therapy/Monitor Closely. Coadministration of ferric maltol with certain oral medications may decrease the bioavailability of either ferric maltol and some oral drugs. For oral drugs where reductions in bioavailability may cause clinically significant effects on its safety or efficacy, separate administration of ferric maltol from these drugs. Duration of separation may depend on the absorption of the medication concomitantly administered (eg, time to peak concentration, whether the drug is an immediate or extended release product).

            • fesoterodine

              fesoterodine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              fesoterodine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • flavoxate

              flavoxate decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              flavoxate decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • flecainide

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

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

            • fluphenazine

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

              fluphenazine and thioridazine both increase sedation. Use Caution/Monitor.

            • flurazepam

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

            • formoterol

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

            • foscarnet

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

            • fostemsavir

              thioridazine and fostemsavir both increase QTc interval. Use Caution/Monitor. QTc prolongation reported with higher than recommended doses of fostemsavir.

            • gemtuzumab

              thioridazine and gemtuzumab both increase QTc interval. Use Caution/Monitor.

            • glycopyrrolate

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

            • glycopyrrolate inhaled

              glycopyrrolate inhaled decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              glycopyrrolate inhaled decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • glycopyrronium tosylate topical

              glycopyrronium tosylate topical, thioridazine. 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.

            • guanfacine

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

            • guselkumab

              guselkumab, thioridazine. Other (see comment). Use Caution/Monitor. Comment: Formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, normalizing the formation of CYP450 enzymes. Upon initiation or discontinuation of guselkumab in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect.

            • haloperidol

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

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

              haloperidol and thioridazine both increase sedation. Use Caution/Monitor.

            • henbane

              henbane decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              henbane decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • homatropine

              homatropine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              homatropine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • hydrocodone

              thioridazine will increase the level or effect of hydrocodone by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Hydromorphone (<3% of the circulating parent hydrocodone) is mainly formed by CYP2D6 mediated O-demethylation of hydrocodone. Hydromorphone may contribute to the total analgesic effect of hydrocodone.

            • hydromorphone

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

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

            • hydroxyzine

              hydroxyzine and thioridazine both increase sedation. Use Caution/Monitor.

            • hyoscyamine

              hyoscyamine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              hyoscyamine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • hyoscyamine spray

              thioridazine increases effects of hyoscyamine spray by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

              hyoscyamine spray decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              hyoscyamine spray decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

            • iloperidone

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

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

              thioridazine and iloperidone both increase QTc interval. Modify Therapy/Monitor Closely.

              iloperidone and thioridazine both increase sedation. Use Caution/Monitor.

            • imipramine

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

            • incobotulinumtoxinA

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

            • indacaterol, inhaled

              indacaterol, inhaled, thioridazine. 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

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

            • insulin degludec/insulin aspart

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

            • insulin inhaled

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

            • ipratropium

              ipratropium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              ipratropium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • isoproterenol

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

              thioridazine, 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 thioridazine both increase sedation. Use Caution/Monitor.

            • ketotifen, ophthalmic

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

            • lapatinib

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

            • lasmiditan

              lasmiditan, thioridazine. 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 will increase the level or effect of thioridazine by sedation. Modify Therapy/Monitor Closely. Dosage adjustment may be necessary if lemborexant is coadministered with other CNS depressants because of potentially additive effects.

            • lenvatinib

              thioridazine and lenvatinib both increase QTc interval. Use Caution/Monitor. Lenvatinib prescribing information recommends monitoring ECG closely when coadministered with QT prolonging drugs.

            • levalbuterol

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

            • levofloxacin

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

            • levorphanol

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

            • liraglutide

              thioridazine, 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

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

              thioridazine, 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, thioridazine. Other (see comment). Use Caution/Monitor. Comment: Risk of neurotoxicity. Multiple mechanisms involved.

            • lofepramine

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

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

            • lofexidine

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

              thioridazine will increase the level or effect of lofexidine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Concomitant use of lofexidine with strong CYP2D6 inhibitors may increase lofexidine plasma levels. Monitor for symptoms of orthostasis and bradycardia if coadministered with a CYP2D6 inhibitor. Consider lofexidine dose reduction.

              thioridazine and lofexidine both increase QTc interval. Use Caution/Monitor. ECG monitoring is recommended.

            • loprazolam

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

            • lorazepam

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

            • lorcaserin

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

            • lormetazepam

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

            • loxapine

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

              loxapine and thioridazine both increase sedation. Use Caution/Monitor.

            • loxapine inhaled

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

              loxapine inhaled and thioridazine both increase sedation. Use Caution/Monitor.

            • lurasidone

              lurasidone, thioridazine. 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

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

            • marijuana

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

            • meclizine

              meclizine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              meclizine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • melatonin

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

            • meperidine

              meperidine and thioridazine both increase sedation. Use Caution/Monitor.

            • meprobamate

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

            • metaproterenol

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

            • metaxalone

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

            • metformin

              thioridazine 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

              thioridazine and methadone both increase QTc interval. Modify Therapy/Monitor Closely.

              methadone and thioridazine both increase sedation. Use Caution/Monitor.

            • methamphetamine

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

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

              thioridazine, 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 thioridazine both increase sedation. Use Caution/Monitor.

            • methoxsalen

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

            • methscopolamine

              methscopolamine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              methscopolamine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • methylenedioxymethamphetamine

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

              thioridazine, 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.

            • methylphenidate

              thioridazine, 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.

            • metoclopramide

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

            • metoprolol

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

            • mexiletine

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

            • midazolam

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

            • midazolam intranasal

              midazolam intranasal, thioridazine. 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

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

              thioridazine, 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.

            • mirabegron

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

            • mirtazapine

              thioridazine and mirtazapine both increase sedation. Use Caution/Monitor.

            • modafinil

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

            • morphine

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

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

            • motherwort

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

            • moxonidine

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

            • nabilone

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

            • nalbuphine

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

            • nebivolol

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

            • norepinephrine

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

              thioridazine, 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

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

            • ofloxacin

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

            • olanzapine

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

              olanzapine and thioridazine both increase sedation. Use Caution/Monitor.

            • oliceridine

              thioridazine will increase the level or effect of oliceridine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. If concomitant use is necessary, may require less frequent oliceridine dosing. Closely monitor for respiratory depression and sedation and titrate subsequent doses accordingly. If inhibitor is discontinued, consider increase oliceridine dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal.

              oliceridine, thioridazine. 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

              thioridazine 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 thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              onabotulinumtoxinA decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • opium tincture

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

            • orphenadrine

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

            • osilodrostat

              osilodrostat and thioridazine both increase QTc interval. Use Caution/Monitor.

            • osimertinib

              osimertinib and thioridazine both increase QTc interval. Use Caution/Monitor. Conduct periodic monitoring with ECGs and electrolytes in patients taking drugs known to prolong the QTc interval.

            • oxaliplatin

              oxaliplatin will increase the level or effect of thioridazine by Other (see comment). Use Caution/Monitor. Monitor for ECG changes if therapy is initiated in patients with drugs known to prolong QT interval.

            • oxazepam

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

            • oxybutynin

              oxybutynin decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              oxybutynin decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • oxybutynin topical

              oxybutynin topical decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              oxybutynin topical decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

              thioridazine increases effects of oxybutynin topical by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

            • oxybutynin transdermal

              oxybutynin transdermal decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              oxybutynin transdermal decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

              thioridazine increases effects of oxybutynin transdermal by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

            • oxycodone

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

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

            • oxymorphone

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

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

            • ozanimod

              ozanimod and thioridazine both increase QTc interval. Modify Therapy/Monitor Closely. The potential additive effects on heart rate, treatment with ozanimod should generally not be initiated in patients who are concurrently treated with QT prolonging drugs with known arrhythmogenic properties.

            • paliperidone

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

              thioridazine and paliperidone both increase QTc interval. Modify Therapy/Monitor Closely.

              paliperidone and thioridazine both increase sedation. Use Caution/Monitor.

            • pancuronium

              pancuronium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              pancuronium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • panobinostat

              panobinostat will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Panobinostat can increase the levels and effects of sensitive CYP2D6 substrates or those with a narrow therapeutic index CYP2D6.

            • papaveretum

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

            • papaverine

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

            • pazopanib

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

            • peginterferon alfa 2b

              peginterferon alfa 2b, thioridazine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.

            • pentazocine

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

            • pentobarbital

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

            • perphenazine

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

              perphenazine and thioridazine both increase sedation. Use Caution/Monitor.

            • phendimetrazine

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

              thioridazine, 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.

            • phenobarbital

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

            • phentermine

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

              thioridazine, 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

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

              thioridazine, 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

              thioridazine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .

              thioridazine, 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

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

            • pimozide

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

              pimozide and thioridazine both increase sedation. Use Caution/Monitor.

            • pirbuterol

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

            • pitolisant

              thioridazine will increase the level or effect of pitolisant by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. If coadministered with strong CYP2D6 inhibitors, initiate pitolisant at 8.9 mg/day and increase after 7 days to maximum of 17.8 mg/day. For patients currently taking pitolisant, reduce pitolisant dose by half upon initiating strong CYP2D6 inhibitors.

            • porfimer

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

            • posaconazole

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

            • pralidoxime

              pralidoxime decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              pralidoxime decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • primidone

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

            • procarbazine

              procarbazine, thioridazine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Excessive sedation.

            • prochlorperazine

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

              prochlorperazine and thioridazine both increase sedation. Use Caution/Monitor.

            • promethazine

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

              promethazine and thioridazine both increase sedation. Use Caution/Monitor.

            • propantheline

              propantheline decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              propantheline decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • propofol

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

            • propylhexedrine

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

              thioridazine, 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

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

            • pseudoephedrine

              thioridazine, 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 thioridazine both increase sedation. Use Caution/Monitor.

            • quetiapine

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

              quetiapine and thioridazine both increase sedation. Use Caution/Monitor.

              quetiapine, thioridazine. Either increases toxicity of the other by QTc interval. Use Caution/Monitor. Avoid use with drugs that prolong QT and in patients with risk factors for prolonged QT interval. Postmarketing cases show QT prolongation with overdose in patients with concomitant illness or with drugs known to cause electrolyte imbalance or prolong QT.

            • ramelteon

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

            • ranolazine

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

            • rapacuronium

              rapacuronium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              rapacuronium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • rilpivirine

              rilpivirine increases toxicity of thioridazine by QTc interval. Use Caution/Monitor. Rilpivirine should be used with caution when co-administered with a drug with a known risk of Torsade de Pointes.

            • rimabotulinumtoxinB

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

              thioridazine and risperidone both increase QTc interval. Modify Therapy/Monitor Closely.

              risperidone and thioridazine both increase sedation. Use Caution/Monitor.

            • rocuronium

              rocuronium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              rocuronium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • romidepsin

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

            • salmeterol

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

            • saquinavir

              saquinavir, thioridazine. Either increases toxicity of the other by QTc interval. Modify Therapy/Monitor Closely. Use alternatives if available.

            • scopolamine

              scopolamine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              scopolamine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • scullcap

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

            • secobarbital

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

            • selpercatinib

              selpercatinib increases toxicity of thioridazine by QTc interval. Use Caution/Monitor.

            • sevoflurane

              sevoflurane and thioridazine both increase sedation. Use Caution/Monitor.

            • shepherd's purse

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

            • smoking

              smoking decreases levels of thioridazine 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 toxicity of thioridazine by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .

            • sodium sulfate/potassium sulfate/magnesium sulfate

              sodium sulfate/potassium sulfate/magnesium sulfate increases toxicity of thioridazine by QTc interval. Use Caution/Monitor. Consider predose and post-colonoscopy ECGs in patients at increased risk of serious cardiac arrhythmias. .

            • solifenacin

              solifenacin decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              solifenacin decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • stiripentol

              stiripentol, thioridazine. Either decreases toxicity of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.

            • sufentanil

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

            • sulfamethoxazole

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

            • tamsulosin

              thioridazine increases levels of tamsulosin by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.

            • tapentadol

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

            • teduglutide

              teduglutide increases levels of thioridazine 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

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

            • temazepam

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

            • terbinafine

              terbinafine will increase the level or effect of thioridazine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Assess need to reduce dose of CYP2D6-metabolized drug.

            • terbutaline

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

            • tetrabenazine

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

            • thiothixene

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

              thioridazine and thiothixene both increase sedation. Use Caution/Monitor.

            • timolol

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

            • tiotropium

              tiotropium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              tiotropium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • tobacco use

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

            • tolterodine

              tolterodine decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              tolterodine decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • topiramate

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

            • tramadol

              thioridazine decreases effects of tramadol by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Decreased conversion of tramadol to active metabolite.

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

              thioridazine decreases effects of tramadol by decreasing metabolism. Use Caution/Monitor. Decreased conversion of tramadol to active metabolite.

            • trazodone

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

            • triazolam

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

            • triclabendazole

              triclabendazole and thioridazine both increase QTc interval. Use Caution/Monitor.

            • triclofos

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

            • trifluoperazine

              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.

            • trihexyphenidyl

              trihexyphenidyl decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

              thioridazine increases effects of trihexyphenidyl by pharmacodynamic synergism. Use Caution/Monitor. Potential for additive anticholinergic effects.

            • trimethoprim

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

            • trimipramine

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

            • triprolidine

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

            • tropisetron

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

            • trospium chloride

              trospium chloride decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              trospium chloride decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

              thioridazine increases effects of trospium chloride by pharmacodynamic synergism. Use Caution/Monitor. Additive anticholinergic effects, possible hypoglycemia.

            • ustekinumab

              ustekinumab, thioridazine. Other (see comment). Use Caution/Monitor. Comment: Formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, normalizing the formation of CYP450 enzymes. Upon initiation or discontinuation of ustekinumab in patients who are receiving concomitant CYP450 substrates, particularly those with a narrow therapeutic index, consider monitoring for therapeutic effect.

            • vecuronium

              vecuronium decreases levels of thioridazine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor.

              vecuronium decreases levels of thioridazine by pharmacodynamic antagonism. Use Caution/Monitor.

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

            • voclosporin

              voclosporin, thioridazine. Either increases effects of the other by QTc interval. Use Caution/Monitor.

            • voriconazole

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

            • xylometazoline

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

              thioridazine, 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

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

              thioridazine, 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

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

            • ziprasidone

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

              thioridazine and ziprasidone both increase sedation. Use Caution/Monitor.

            • zolpidem

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

            • zotepine

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

              thioridazine and zotepine both increase sedation. Use Caution/Monitor.

            Minor (70)

            • amantadine

              amantadine increases toxicity of thioridazine by pharmacodynamic synergism. Minor/Significance Unknown. May increase Parkinsonian tremor.

            • amitriptyline

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

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

            • amobarbital

              thioridazine decreases levels of amobarbital by unspecified interaction mechanism. Minor/Significance Unknown.

            • amoxapine

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

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

            • aripiprazole

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

            • atropine

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

            • atropine IV/IM

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

            • benazepril

              thioridazine, benazepril. Either increases effects of the other by pharmacodynamic synergism. Minor/Significance Unknown. May increase risk of hypotension.

            • brimonidine

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

            • bupropion

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

            • butabarbital

              thioridazine decreases levels of butabarbital by unspecified interaction mechanism. Minor/Significance Unknown.

            • butalbital

              thioridazine decreases levels of butalbital by unspecified interaction mechanism. Minor/Significance Unknown.

            • captopril

              thioridazine increases effects of captopril by unspecified interaction mechanism. Minor/Significance Unknown.

            • chasteberry

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

            • chloroquine

              chloroquine increases levels of thioridazine by decreasing metabolism. Minor/Significance Unknown.

            • chlorpromazine

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

            • clomipramine

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

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

            • codeine

              thioridazine decreases effects of codeine by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of codeine to active metabolite morphine.

            • desipramine

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

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

            • dexfenfluramine

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

            • dextroamphetamine

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

            • dextromethorphan

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

            • donepezil

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

            • doxepin

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

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

            • enalapril

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

            • encainide

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

            • ethanol

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

            • eucalyptus

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

            • fesoterodine

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

            • fluphenazine

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

            • fosinopril

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

            • galantamine

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

            • glycopyrrolate

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

            • glycopyrrolate inhaled

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

            • imidapril

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

            • imipramine

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

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

            • lisinopril

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

            • lofepramine

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

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

            • loratadine

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

            • maprotiline

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

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

            • metyrapone

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

            • metyrosine

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

            • moexipril

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

            • nortriptyline

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

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

            • oxybutynin

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

            • oxybutynin topical

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

            • oxybutynin transdermal

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

            • oxycodone

              thioridazine decreases effects of oxycodone by decreasing metabolism. Minor/Significance Unknown. Decreased conversion of oxycodone to active metabolite morphine.

            • pentobarbital

              thioridazine decreases levels of pentobarbital by unspecified interaction mechanism. Minor/Significance Unknown.

            • perhexiline

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

            • perindopril

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

            • perphenazine

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

            • phenobarbital

              thioridazine decreases levels of phenobarbital by unspecified interaction mechanism. Minor/Significance Unknown.

            • primidone

              thioridazine decreases levels of primidone by unspecified interaction mechanism. Minor/Significance Unknown.

            • prochlorperazine

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

            • promazine

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

            • promethazine

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

            • protriptyline

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

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

            • pyrimethamine

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

            • quinapril

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

            • ramipril

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

            • risperidone

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

            • sage

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

            • secobarbital

              thioridazine decreases levels of secobarbital by unspecified interaction mechanism. Minor/Significance Unknown.

            • tolterodine

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

            • trandolapril

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

            • trazodone

              trazodone, thioridazine. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown. Additive hypotensive effects.

              trazodone, thioridazine. Either increases levels of the other by decreasing metabolism. Minor/Significance Unknown. Additive anticholinergic effects.

            • trifluoperazine

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

            • trimipramine

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

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

            • tropisetron

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

            Previous
            Next:

            Adverse Effects

            Frequency Not Defined

            EPS (muscle stiffness, dystonia, parkinsonism, tardive dyskinesia, akathisia) (60%)

            NMS (infrequent but serious)

            Sedation

            Anticholinergic effects

            Weight gain

            Oligomenorrhea/amenorrhea

            Erectile dysfunction

            Insomnia

            Restlessness

            Anxiety

            Euphoria

            Agitation

            Depression

            Weakness

            Headache

            Cerebral edema

            Poikilothermia

            Orthostatic hypotension

            Tachycardia

            Dizziness

            Lens opacities (prolonged use)

            Anorexia

            Dyspepsia

            Constipation

            Ileus

            Blood dyscrasia

            ECG changes

            Photosensitivity

            Pruritis

            Diarrhea

            Galactorrhea

            Ejaculatory disorder

            Seizure (rare)

            Priapism (rare)

            Cholestatic jaundice (rare)

            Previous
            Next:

            Warnings

            Black Box Warnings

            Patients with dementia-related psychosis who are treated with antipsychotic drugs are at an increased risk of death as shown in short-term controlled trials. The deaths appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature

            This drug is not approved for the treatment of patients with dementia-related psychosis

            Contraindications

            Documented hypersensitivity to phenothiazines

            Coma, severe hypotension, severe CNS depression, concurrency with large amounts of CNS depressants, poorly controlled seizure disorder, myelosuppression, subcortical brain damage

            Any drugs or conditions that prolong QTc interval

            Lactation

            Cautions

            Avoid using in children with suspected Reye's syndrome

            Glaucoma, prostatic hypertrophy, stenosing PUD, tardive dyskinesia, history of NMS, Parkinson's disease, hypocalcemia, renal/hepatic impairment, patients who have exhibited a severe reaction to insulin or ECT, history of seizures, asthma, respiratory tract infections, cardiovascular disease

            Risk of EPS, NMS, hypotension

            Hypotension may be particularly severe in patients with pheochromocytoma or mitral insufficiency

            Depresses hypothalamic thermoregulatory mechanism; exposure to extreme temperatures may cause hypo- or hyperthermia

            In case of severe hypotension, use norepinephrine or phenylepinephrine, do NOT use epinephrine or dopamine

            May need anticholinergic antiparkinsonian agent to counter EPS

            Sales being discontinued in Canada

            FDA Warning regarding off-label use for dementia in elderly

            Previous
            Next:

            Pregnancy & Lactation

            Pregnancy Category: C

            Lactation: unknown

            Pregnancy Categories

            A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA: Information not available.

            Previous
            Next:

            Pharmacology

            Mechanism of Action

            Piperazine phenothiazine agent; antagonist for the postsynaptic mesolimbic dopaminergic D2 receptors in the brain; decreases the release of hypothalamic and hypophyseal hormones

            Pharmacokinetics

            Half-Life elimination: 24 hr

            Metabolism: Hepatic P450 enzyme CYP2D6

            Enzymes inhibited: CYP2D6

            Protein bound: 95%

            Duration: 4-5 days

            Previous
            Next:

            Images

            BRAND FORM. UNIT PRICE PILL IMAGE
            thioridazine oral
            -
            10 mg tablet
            thioridazine oral
            -
            25 mg tablet
            thioridazine oral
            -
            100 mg tablet
            thioridazine oral
            -
            100 mg tablet
            thioridazine oral
            -
            50 mg tablet
            thioridazine oral
            -
            25 mg tablet
            thioridazine oral
            -
            10 mg tablet
            thioridazine oral
            -
            50 mg tablet

            Copyright © 2010 First DataBank, Inc.

            Previous
            Next:

            Patient Handout

            Patient Education
            thioridazine oral

            THIORIDAZINE - ORAL

            (thigh-oh-RID-uh-zeen)

            COMMON BRAND NAME(S): Mellaril

            WARNING: Thioridazine rarely has caused very serious (possibly fatal) irregular heartbeat (QT prolongation in the EKG). It should be used only in patients who have not shown improvement with at least 2 other antipsychotic medications or who cannot tolerate other antipsychotic medications. This medication should not be used with other medications that can also cause a slow or irregular heartbeat. (See also Drug Interactions.)There may be a slightly increased risk of serious, possibly fatal side effects (such as heart failure, fast/irregular heartbeat, pneumonia) when this medication is used by older adults with dementia. This medication is not approved for the treatment of dementia-related behavior problems. Discuss the risks and benefits of this medication, as well as other effective and possibly safer treatments for dementia-related behavior problems, with the doctor.

            USES: This medication is used to treat certain mental/mood disorders (e.g., schizophrenia). This medication helps you to think more clearly, feel less nervous, and take part in everyday life. It can also help prevent suicide in people likely to harm themselves and reduce aggression and the desire to hurt others. It can help decrease your negative thoughts and hallucinations. Thioridazine belongs to a class of drugs known as phenothiazines.

            HOW TO USE: Take this medication by mouth with or without food as directed by your doctor, usually 2 to 4 times a day.Dosage is based on your medical condition and response to therapy. Once your condition improves and you are better for a while, your doctor may work with you to reduce your regular dose. This may be done over time. Do not stop your medication or lower your dose without talking with your doctor first. Some conditions may become worse when the drug is stopped abruptly. Your dose may need to be gradually reduced.Use this medication regularly in order to get the most benefit from it. To help you remember, use it at the same times each day.Inform your doctor if your condition persists or worsens.

            SIDE EFFECTS: Dizziness, lightheadedness, drowsiness, difficulty urinating, constipation, restlessness, headache, and blurred vision may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.Dizziness and lightheadedness can increase the risk of falling. Get up slowly when rising from a sitting or lying position.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: shakiness (tremors), mask-like facial expression, jerking movements while walking, signs of infection (e.g., fever, persistent sore throat), vision changes (e.g., vision loss, sudden difficulty seeing at night, brown-tinged vision).Get medical help right away if you have any very serious side effects, including: severe dizziness, fainting, slow heartbeat, seizures.Thioridazine may rarely cause a condition known as tardive dyskinesia. In some cases this condition may be permanent. Tell your doctor right away if you develop any unusual/uncontrolled movements (especially of the face, lips, tongue, arms or legs).In rare cases, thioridazine may increase your level of a certain chemical made by the body (prolactin). For females, this increase in prolactin may result in unwanted breast milk, missed/stopped periods, or difficulty becoming pregnant. For males, it may result in decreased sexual ability, inability to produce sperm, or enlarged breasts. If you develop any of these symptoms, tell your doctor right away.This medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms: fever, muscle stiffness/pain/tenderness/weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, signs of kidney problems (such as change in the amount of urine).A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

            PRECAUTIONS: Before taking thioridazine, tell your doctor or pharmacist if you are allergic to it; or to other phenothiazines (e.g., chlorpromazine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: nervous system problems (such as seizures, drug/alcohol overdose, severe drowsiness), blood pressure problems, certain blood problems (such as low white blood cell count), Parkinson's disease, low enzymes needed to remove drugs from the body (slow hydroxylator).Thioridazine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away.The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may cause QT prolongation. Before using thioridazine, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using thioridazine safely.This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist that you are taking this medication.This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.Older adults may be more sensitive to the side effects of this drug, especially dizziness, lightheadedness, drowsiness, confusion, constipation, difficulty urinating, and QT prolongation (see above). Dizziness, lightheadedness, drowsiness, and confusion can increase the risk of falling.During pregnancy, this medication should be used only when clearly needed. Babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn especially during their first month, tell the doctor right away.Since untreated mental/mood problems (such as schizophrenia, depression) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy.It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.

            DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: cabergoline, lithium, certain products used to treat chronic hepatitis C (asunaprevir, ombitasvir/paritaprevir/ritonavir), medications for Parkinson's disease (such as levodopa).Many drugs besides thioridazine may affect the heart rhythm (QT prolongation), including amiodarone, cisapride, dofetilide, pimozide, procainamide, quinidine, sotalol, macrolide antibiotics (such as erythromycin), ziprasidone, among others. Before using thioridazine, report all medications you are currently using to your doctor or pharmacist.Other medications can affect the removal of thioridazine from your body, which may affect how thioridazine works. Examples include bupropion, cinacalcet, dacomitinib, duloxetine, mirabegron, pindolol, propranolol, rolapitant, terbinafine, certain SSRI antidepressants (such as fluoxetine, fluvoxamine, paroxetine), among others.Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

            OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.

            NOTES: Do not share this medication with others.Laboratory and/or medical tests (e.g., eye exams, potassium levels, EKG) may be performed from time to time to monitor your progress or check for side effects. Consult your doctor for more details.

            MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

            STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

            Information last revised August 2021. Copyright(c) 2021 First Databank, Inc.

            IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

            Previous
            Next:

            Formulary

            FormularyPatient Discounts

            Adding plans allows you to compare formulary status to other drugs in the same class.

            To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.

            Adding plans allows you to:

            • View the formulary and any restrictions for each plan.
            • Manage and view all your plans together – even plans in different states.
            • Compare formulary status to other drugs in the same class.
            • Access your plan list on any device – mobile or desktop.

            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
            Additional Offers
            Email to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Email Forms to Patient

            From:

            To:

            The recipient will receive more details and instructions to access this offer.

            By clicking send, you acknowledge that you have permission to email the recipient with this information.

            Previous
            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.