nafcillin (Rx)

Brand and Other Names:Nafcil, Nallpen
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

injectable solution

  • 20mg/mL
  • 2g/100mL

powder for injection

  • 1g
  • 2g
  • 10g

Susceptible Infections

500 mg IV/IM q4-6hr

Severe Infections

1 g IV/IM q4hr

Staphylococcal Endocarditis

2 g IV q4hr for 4-6 weeks; may be longer and may add rifampin and gentamicin if prosthetics present

Bursitis septic

2 g IV q4hr

Administration

Initial therapy for suspected penicillin G-resistant streptococcal or staphylococcal infections.

Use parenteral therapy initially in severe infections.

Change to oral therapy as condition warrants. Due to thrombophlebitis, particularly in the elderly, administer parenterally only for short term (1-2 d); change to oral route as clinically indicated.

Renal Impairment

Dose adjustment not necessary unless concomitant hepatic failure present

Hepatic Impairment

Dose adjustment not necessary unless concomitant renal failure present

Dosage Forms & Strengths

injectable solution

  • 20mg/mL
  • 2g/100mL

powder for injection

  • 1g
  • 2g
  • 10g

Susceptible Infections

50-100 mg/kg/day IV/IM divided q6hr  

Maximum 12g/day

Severe Infections

100-200 mg/kg/day IV/IM divided q6hr  

Staphylococcal Endocarditis

200mg/kg/day IV divided q4-6hr for 6 weeks; may be longer and may add rifampin and gentamicin if prosthetics present  

Neonates (<28 Days Old)

(<7 days old, <2 kg) OR (>7 days old, <1.2 kg): 50 mg/kg/day IV/IM divided q12hr  

(<7 days old, >2 kg) OR (>7 days old, 1.2-2 kg): 75 mg/kg/day IV/IM divided q8hr

(>7 days old, >2 kg): 100-140 mg/kg/day IV/IM divided q6hr

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Interactions

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            Contraindicated (18)

            • cariprazine

              nafcillin will decrease the level or effect of cariprazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. CYP3A4 is responsible for the formation and elimination of cariprazine's active metabolites. The effect of CYP3A4 inducers on cariprazine exposure has not been evaluated and the net effect is unclear.

            • cobimetinib

              nafcillin will decrease the level or effect of cobimetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Avoid coadministration. Strong or moderate CYP3A inducers may decrease cobimetinib systemic exposure by >80% and reduce its efficacy.

            • dienogest/estradiol valerate

              nafcillin will decrease the level or effect of dienogest/estradiol valerate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Women should not choose estradiol valerate/dienogest as their contraceptive while using strong CYP3A4 inducers due to potential decrease in contraceptive efficacy. Estradiol valerate/dienogest should not be used for at least 28 days after discontinuation of the inducer due to possibility of decreased contraceptive efficacy.

            • doravirine

              nafcillin will decrease the level or effect of doravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of doravirine with a strong CYP3A inducer may decrease doravirine plasma concentrations and/or effects. Potential for loss of virologic response and possible resistance to doravirine.

            • elvitegravir/cobicistat/emtricitabine/tenofovir DF

              nafcillin decreases levels of elvitegravir/cobicistat/emtricitabine/tenofovir DF by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. May lead to loss of virologic response and possible resistance.

            • fostemsavir

              nafcillin will decrease the level or effect of fostemsavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of fostemsavir (prodrug) with strong CYP3A4 inducers significantly decreases temsavir (active moiety) plasma concentrations, which may lead to loss of virologic response and resistance.

            • isavuconazonium sulfate

              nafcillin will decrease the level or effect of isavuconazonium sulfate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • lonafarnib

              nafcillin will decrease the level or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is a sensitive CYP3A4 substrate. Coadministration with strong or moderate CYP3A4 inducers is contraindicated.

            • lorlatinib

              nafcillin will decrease the level or effect of lorlatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration of lorlatinib with strong CYP3A inducers is contraindicated. Discontinue the strong CYP3A inducer for 3 plasma half-lives before initiating lorlatinib.

            • lumacaftor/ivacaftor

              nafcillin will decrease the level or effect of lumacaftor/ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A inducers have minimal effect on lumacaftor exposure, but decreased ivacaftor exposure (AUC) by 57%. This may reduce the effectiveness of lumacaftor/ivacaftor. Therefore, coadministration is not recommended.

            • lumefantrine

              nafcillin will decrease the level or effect of lumefantrine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration with strong CYP3A4 inducers can result in decreased serum concentrations and loss of antimalarial efficacy

            • naloxegol

              nafcillin will decrease the level or effect of naloxegol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Use of naloxegol with strong CYP3A4 inducers is not recommended

            • ombitasvir/paritaprevir/ritonavir & dasabuvir

              nafcillin will decrease the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inducers may reduce partiaprevir and ritonavir levels, and therefore decreased efficacy of Viekira Pak

            • panobinostat

              nafcillin decreases levels of panobinostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inducers can reduce panobinostat levels by ~70% and lead to treatment failure.

            • praziquantel

              nafcillin decreases levels of praziquantel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP450 inducers significantly decrease praziquantel blood levels.

            • regorafenib

              nafcillin, regorafenib. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inducers decrease regorafenib levels and increase exposure of the active metabolite M-5.

            • roflumilast

              nafcillin will decrease the level or effect of roflumilast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Coadministration not recommended; strong cytochrome P450 enzyme inducers decrease systemic exposure to roflumilast and may reduce the therapeutic effectiveness

            • vandetanib

              nafcillin decreases levels of vandetanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Avoid coadministration with potent CYP3A4 inducers; these drugs reduce exposure to vandetanib by up to 40%.

            Serious - Use Alternative (106)

            • abemaciclib

              nafcillin will decrease the level or effect of abemaciclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of abemaciclib with strong CYP3A4 inducers reduces plasma concentration of abemaciclib and its metabolites.

            • alpelisib

              nafcillin will decrease the level or effect of alpelisib by pharmacodynamic synergism. Avoid or Use Alternate Drug. Avoid coadministration of alpelisib (CYP3A4 substrate) with strong CYP3A4 inducers.

            • apremilast

              nafcillin will decrease the level or effect of apremilast by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong CYP inducers results in a significant decrease of systemic exposure of apremilast, which may result in loss of efficacy

            • avapritinib

              nafcillin will decrease the level or effect of avapritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • axitinib

              nafcillin decreases levels of axitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Selection of concomitant medication with no or minimal CYP3A4 induction potential is recommended.

            • BCG vaccine live

              nafcillin decreases effects of BCG vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until Abx Tx complete to administer live bacterial vaccine.

            • bedaquiline

              nafcillin will decrease the level or effect of bedaquiline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of bedaquiline with strong CYP3A4 inducers due to potential for decreased therapeutic effect

            • bosutinib

              nafcillin decreases levels of bosutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inducers decreased bosutinib plasma concentration by ~85%.

            • brigatinib

              nafcillin will decrease the level or effect of brigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong CYP3A4 inducers may decrease brigatinib efficacy.

            • cabozantinib

              nafcillin will decrease the level or effect of cabozantinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of cabozantinib with strong CYP3A4 inducers. If a strong CYP3A4 inducer is required, increase cabozantinib dose by 40 mg/day (Cometriq) or by 20 mg/day (Cabometyx). Resume previous dose 2-3 days after strong CYP3A4 inducer discontinued.

            • calcitriol

              nafcillin will decrease the level or effect of calcitriol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • capmatinib

              nafcillin will decrease the level or effect of capmatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ceritinib

              nafcillin decreases levels of ceritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • cholera vaccine

              nafcillin, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.

            • cobicistat

              nafcillin will decrease the level or effect of cobicistat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • copanlisib

              nafcillin will decrease the level or effect of copanlisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of copanlisib with strong CYP3A4 inducers.

            • deflazacort

              nafcillin will decrease the level or effect of deflazacort by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of deflazacort with moderate or strong CYP3A4 inducers.

            • demeclocycline

              demeclocycline decreases effects of nafcillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • doxycycline

              doxycycline decreases effects of nafcillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • dronedarone

              nafcillin will decrease the level or effect of dronedarone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • duvelisib

              nafcillin will decrease the level or effect of duvelisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with a strong CYP3A inducer decreases duvelisib area under the curve (AUC), which may reduce duvelisib efficacy.

            • elbasvir/grazoprevir

              nafcillin will decrease the level or effect of elbasvir/grazoprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. The therapeutic effect of elbasvir/grazoprevir may be reduced if coadministered with moderate CYP3A inducers and should be avoided.

            • eliglustat

              nafcillin will decrease the level or effect of eliglustat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A inducers significantly decreases eliglustat exposure; coadministration not recommended

            • elvitegravir

              nafcillin will decrease the level or effect of elvitegravir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid; coadministration with CYP3A inducers may result in decreased plasma concentrations of elvitegravir and/or a concomitantly administered protease inhibitor and lead to loss of therapeutic effect and to possible resistance

            • encorafenib

              nafcillin will decrease the level or effect of encorafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • entrectinib

              nafcillin will decrease the level or effect of entrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erdafitinib

              nafcillin will decrease the level or effect of erdafitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • erythromycin ethylsuccinate

              nafcillin will decrease the level or effect of erythromycin ethylsuccinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • erythromycin lactobionate

              nafcillin will decrease the level or effect of erythromycin lactobionate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • erythromycin stearate

              nafcillin will decrease the level or effect of erythromycin stearate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • everolimus

              nafcillin will decrease the level or effect of everolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • fedratinib

              nafcillin will decrease the level or effect of fedratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Effect of coadministering a strong CYP3A4 inducer with fedratinib has not been studied.

            • fexinidazole

              nafcillin will increase the level or effect of fexinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. CYP450 inducers may significantly increase plasma concentrations of fexinidazole?s active metabolites: fexinidazole sulfoxide (M1) and fexinidazole sulfone (M2). M2 plasma concentrations associated with increased QT prolongation risks.

            • finerenone

              nafcillin will decrease the level or effect of finerenone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • fostamatinib

              nafcillin will decrease the level or effect of fostamatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • glasdegib

              nafcillin will decrease the level or effect of glasdegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of glasdegib with strong CYP3A inducers.

            • ibrutinib

              nafcillin decreases levels of ibrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A inducers decrease ibrutinib plasma concentrations by ~10-fold.

            • idelalisib

              nafcillin will decrease the level or effect of idelalisib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration; strong CYP3A4 inducers significantly decrease idelalisib systemic exposure

            • infigratinib

              nafcillin will decrease the level or effect of infigratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • irinotecan

              nafcillin will decrease the level or effect of irinotecan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • irinotecan liposomal

              nafcillin will decrease the level or effect of irinotecan liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • istradefylline

              nafcillin will decrease the level or effect of istradefylline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of istradefylline with strong CYP3A4 inducers.

            • ivabradine

              nafcillin will decrease the level or effect of ivabradine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of ivabradine with moderate CYP3A4 inducers.

            • ivacaftor

              nafcillin decreases levels of ivacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with strong CYP3A4 inducers; systemic exposure of ivacaftor substantially reduced (ie, ~9-fold).

            • ivosidenib

              nafcillin will decrease the level or effect of ivosidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of ivosidenib with strong CYP3A4 inducers decreased ivosidenib plasma concentrations.

            • ixazomib

              nafcillin will decrease the level or effect of ixazomib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of ixazomib with strong CYP3A inducers. Strong inducers have been shown to decrease ixazomib Cmax by 54% and AUC by 74%.

            • larotrectinib

              nafcillin will decrease the level or effect of larotrectinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration of larotrectinib with strong CYP3A4 inducers is unavoidable, double larotrectinib dose. Resume prior larotrectinib dose once CYP3A4 inducer discontinued for 3-5 half-lives

            • lefamulin

              nafcillin will decrease the level or effect of lefamulin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of lefamulin with strong or moderate CYP3A inducers unless the benefit outweighs risks. Monitor for reduced efficacy.

            • lemborexant

              nafcillin will decrease the level or effect of lemborexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • lovastatin

              nafcillin will decrease the level or effect of lovastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • lurbinectedin

              nafcillin will decrease the level or effect of lurbinectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • macimorelin

              nafcillin will decrease the level or effect of macimorelin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potential for false positive test results if macimorelin and strong CYP3A4 inducers are coadministered. Discontinue strong CYP3A4 inducer, allowing for sufficient washout time, before testing.

            • macitentan

              nafcillin will decrease the level or effect of macitentan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministering macitentan with strong CYP3A4 inducers

            • midostaurin

              nafcillin will decrease the level or effect of midostaurin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong CYP3A4 inducers may decrease midostaurin concentrations resulting in reduced efficacy.

            • minocycline

              minocycline decreases effects of nafcillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • mobocertinib

              nafcillin will decrease the level or effect of mobocertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • mycophenolate

              nafcillin, mycophenolate. Either increases levels of the other by decreasing renal clearance. Avoid or Use Alternate Drug.

            • neratinib

              nafcillin will decrease the level or effect of neratinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of neratinib with strong/moderate CYP3A4 inducers.

            • netupitant/palonosetron

              nafcillin will decrease the level or effect of netupitant/palonosetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Netupitant is mainly metabolized by CYP3A4; avoid use in patients who are chronically using a strong CYP3A4 inducer

            • olaparib

              nafcillin will decrease the level or effect of olaparib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration with moderate CYP3A inducers cannot be avoided, be aware of a potential for decreased efficacy of olaparib

            • omadacycline

              omadacycline decreases effects of nafcillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.

            • osimertinib

              nafcillin will decrease the level or effect of osimertinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of osimertinib with strong CYP3A inducers.

            • pemigatinib

              nafcillin will decrease the level or effect of pemigatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • perampanel

              nafcillin will decrease the level or effect of perampanel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • pexidartinib

              nafcillin will decrease the level or effect of pexidartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • pomalidomide

              nafcillin decreases levels of pomalidomide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ponatinib

              nafcillin decreases levels of ponatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid unless the coadministration outweighs the possible risk of ponatinib underexposure; monitor for signs of reduced efficacy.

            • pralsetinib

              nafcillin will decrease the level or effect of pralsetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid, double current pralsetinib dose starting on Day 7 of coadministration with strong CYP3A inducer. After inducer has been discontinued for at least 14 days, resume previous pralsetinib dose.

            • pretomanid

              nafcillin will decrease the level or effect of pretomanid by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Pretomanid is a CYP3A4 substrate. Avoid coadministration of strong or moderate CYP3A4 inducers.

            • probenecid

              nafcillin, probenecid. Either increases levels of the other by decreasing renal clearance. Avoid or Use Alternate Drug.

            • ranolazine

              nafcillin will decrease the level or effect of ranolazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • rimegepant

              nafcillin will decrease the level or effect of rimegepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • ripretinib

              nafcillin will decrease the level or effect of ripretinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with a strong CYP3A inhibitor will decrease systemic exposure to ripretinib and its active metabolite (DP-5439), which may decrease risk of adverse reactions.

            • rolapitant

              nafcillin will decrease the level or effect of rolapitant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Long-term coadministration of strong CYP3A4 inducers with rolapitant may significantly decrease rolapitant efficacy.

            • romidepsin

              nafcillin will decrease the level or effect of romidepsin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration with strong 3A4 inducers should be avoided if possible.

            • sarecycline

              sarecycline decreases effects of nafcillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.

            • selpercatinib

              nafcillin will decrease the level or effect of selpercatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • selumetinib

              nafcillin will decrease the level or effect of selumetinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • sildenafil

              nafcillin will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Potent CYP3A4 inducers are expected to cause substantial decreases in sildenafil plasma levels

            • silodosin

              nafcillin will decrease the level or effect of silodosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • simvastatin

              nafcillin will decrease the level or effect of simvastatin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • siponimod

              nafcillin will decrease the level or effect of siponimod by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of siponimod with a drug that causes moderate CYP2C9 plus a moderate or strong CYP3A4 inducer is not recommended. Coadministration with moderate or strong CYP3A4 inducers alone is not recommended for patients with CYP2C9*1/*3 and*2/*3 genotype.

            • sirolimus

              nafcillin will decrease the level or effect of sirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • sofosbuvir/velpatasvir

              nafcillin will increase the level or effect of sofosbuvir/velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Velpatasvir is a substrate of CYP2B6, CYP2C8, and CYP3A4. Drugs that are moderate-to-potent inducers of CYP2B6, CYP2C8, or CYP3A4 may significantly decrease velpatasvir plasma concentrations, leading to potentially reduced therapeutic effect.

            • sonidegib

              nafcillin will decrease the level or effect of sonidegib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sonidegib with strong or moderate CYP3A4 inducers.

            • sotorasib

              nafcillin will decrease the level or effect of sotorasib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • stiripentol

              nafcillin will decrease the level or effect of stiripentol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If unable to avoid coadministration of stiripentol with strong CYP3A4 inducers, increase stiripentol dose.

            • tazemetostat

              nafcillin will decrease the level or effect of tazemetostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tepotinib

              nafcillin will decrease the level or effect of tepotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tetracycline

              tetracycline decreases effects of nafcillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug.

            • tezacaftor

              nafcillin will decrease the level or effect of tezacaftor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tivozanib

              nafcillin will decrease the level or effect of tivozanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tolvaptan

              nafcillin will decrease the level or effect of tolvaptan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.

            • trabectedin

              nafcillin will decrease the level or effect of trabectedin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • tucatinib

              nafcillin will decrease the level or effect of tucatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • typhoid vaccine live

              nafcillin decreases effects of typhoid vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until Abx Tx complete to administer live bacterial vaccine.

            • ubrogepant

              nafcillin will decrease the level or effect of ubrogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • upadacitinib

              nafcillin will decrease the level or effect of upadacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid upadacitinib coadministration with strong CYP3A4 inducers.

            • velpatasvir

              nafcillin will decrease the level or effect of velpatasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • venetoclax

              nafcillin will decrease the level or effect of venetoclax by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of venetoclax with strong or moderate CYP3A inducers. Consider alternative treatment with agents that have less CYP3A induction.

            • voclosporin

              nafcillin will decrease the level or effect of voclosporin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • vorapaxar

              nafcillin decreases levels of vorapaxar by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • voxelotor

              nafcillin will decrease the level or effect of voxelotor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor is primarily metabolized by CYP3A4. Avoid coadministration with moderate or strong CYP3A4 inducers. If unable to avoid coadministration, increase voxelotor dose (see Dosage Modifications).

            • voxilaprevir

              nafcillin will decrease the level or effect of voxilaprevir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            • warfarin

              nafcillin decreases effects of warfarin by increasing hepatic clearance. Avoid or Use Alternate Drug.

            • zanubrutinib

              nafcillin will decrease the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.

            Monitor Closely (166)

            • abiraterone

              nafcillin decreases levels of abiraterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Avoid coadministration of abiraterone with strong CYP3A4 inducers; if a strong CYP3A4 inducer must be used, increase abiraterone dosage frequency from once daily to twice daily.

            • acalabrutinib

              nafcillin will decrease the level or effect of acalabrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • aspirin

              nafcillin, aspirin. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.

              nafcillin, aspirin. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

            • aspirin rectal

              nafcillin, aspirin rectal. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              nafcillin, aspirin rectal. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.

            • aspirin/citric acid/sodium bicarbonate

              nafcillin, aspirin/citric acid/sodium bicarbonate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              nafcillin, aspirin/citric acid/sodium bicarbonate. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.

            • bazedoxifene/conjugated estrogens

              nafcillin will decrease the level or effect of bazedoxifene/conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

              nafcillin will decrease the level or effect of bazedoxifene/conjugated estrogens by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • bendroflumethiazide

              nafcillin, bendroflumethiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

            • benzhydrocodone/acetaminophen

              nafcillin will decrease the level or effect of benzhydrocodone/acetaminophen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Caution when discontinuing CYP3A4 inducers that are coadministered with benzhydrocodone (prodrug of hydrocodone); plasma concentrations of hydrocodone may increase and can result in potentially fatal respiratory depression.

            • brexpiprazole

              nafcillin will decrease the level or effect of brexpiprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Double brexpiprazole dose over 1-2 weeks if administered with a strong CYP3A4 inducer.

            • bromocriptine

              nafcillin will decrease the level or effect of bromocriptine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • budesonide

              nafcillin will decrease the level or effect of budesonide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • buprenorphine

              nafcillin will decrease the level or effect of buprenorphine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • buprenorphine buccal

              nafcillin will decrease the level or effect of buprenorphine buccal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • buprenorphine subdermal implant

              nafcillin will decrease the level or effect of buprenorphine subdermal implant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor patients already on buprenorphine subdermal implant who require newly-initiated treatment with CYP3A4 inducer for signs and symptoms of withdrawal. If the dose of the concomitant CYP3A4 inducer cannot be reduced or discontinued, implant removal may be necessary and the patient should then be treated with a buprenorphine dosage form that permits dose adjustments. If a CYP3A4 inducer is discontinued in a patient who has been stabilized on buprenorphine, monitor the patient for overmedication.

            • buprenorphine transdermal

              nafcillin will decrease the level or effect of buprenorphine transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • buprenorphine, long-acting injection

              nafcillin will decrease the level or effect of buprenorphine, long-acting injection by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Patients who transfer to buprenorphine long-acting injection from transmucosal buprenorphine coadministered with CYP3A4 inducers should be monitored to ensure buprenorphine plasma levels are adequate. If the buprenorphine dose is inadequate and the CYP3A4 inducer cannot be reduced or discontinued, transition the patient back to a buprenorphine formulation that permits dose adjustments.

            • cabazitaxel

              nafcillin will decrease the level or effect of cabazitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of strong CYP3A4 inducers may decrease cabazitaxel concentrations. Avoid coadministration.

            • calcifediol

              nafcillin, calcifediol. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Drugs that stimulate microsomal hydroxylation reduce the half-life of calcifediol.

            • cannabidiol

              nafcillin will decrease the level or effect of cannabidiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Consider an increase in cannabidiol dosage (based on clinical response and tolerability) when coadministered with a strong CYP3A4 inducer.

            • chloramphenicol

              chloramphenicol decreases effects of nafcillin by pharmacodynamic antagonism. Use Caution/Monitor. Bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • chlordiazepoxide

              nafcillin will decrease the level or effect of chlordiazepoxide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • choline magnesium trisalicylate

              nafcillin, choline magnesium trisalicylate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              nafcillin, choline magnesium trisalicylate. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.

            • citalopram

              nafcillin will decrease the level or effect of citalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • clonazepam

              nafcillin will decrease the level or effect of clonazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • clorazepate

              nafcillin will decrease the level or effect of clorazepate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • conjugated estrogens, vaginal

              nafcillin will decrease the level or effect of conjugated estrogens, vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • crizotinib

              nafcillin will decrease the level or effect of crizotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • cyclosporine

              nafcillin will decrease the level or effect of cyclosporine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • dantrolene

              nafcillin will decrease the level or effect of dantrolene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • darifenacin

              nafcillin will decrease the level or effect of darifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers may increase metabolism of CYP3A4 substrates

            • darunavir

              nafcillin will decrease the level or effect of darunavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • deflazacort

              nafcillin and deflazacort both decrease serum potassium. Use Caution/Monitor.

            • diazepam intranasal

              nafcillin will decrease the level or effect of diazepam intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong or moderate CYP3A4 inducers may increase rate of diazepam elimination; therefore, efficacy of diazepam may be decreased.

            • digoxin

              nafcillin will increase the level or effect of digoxin by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

            • diltiazem

              nafcillin will decrease the level or effect of diltiazem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • doxorubicin

              nafcillin will decrease the level or effect of doxorubicin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers may increase metabolism of CYP3A4 substrates

            • doxorubicin liposomal

              nafcillin will decrease the level or effect of doxorubicin liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers may increase metabolism of CYP3A4 substrates

            • dronabinol

              nafcillin will decrease the level or effect of dronabinol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Dronabinol is a CYP3A4 substrate.

            • efavirenz

              nafcillin will decrease the level or effect of efavirenz by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers may increase metabolism of CYP3A4 substrates

            • elagolix

              nafcillin will decrease the level or effect of elagolix by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • enzalutamide

              nafcillin will decrease the level or effect of enzalutamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • erlotinib

              nafcillin will decrease the level or effect of erlotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • escitalopram

              nafcillin will decrease the level or effect of escitalopram by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estradiol

              nafcillin will decrease the level or effect of estradiol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

              nafcillin will decrease the level or effect of estradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estradiol vaginal

              nafcillin will decrease the level or effect of estradiol vaginal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estrogens conjugated synthetic

              nafcillin will decrease the level or effect of estrogens conjugated synthetic by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

              nafcillin will decrease the level or effect of estrogens conjugated synthetic by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estrogens esterified

              nafcillin will decrease the level or effect of estrogens esterified by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • estropipate

              nafcillin will decrease the level or effect of estropipate by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

              nafcillin will decrease the level or effect of estropipate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • eszopiclone

              nafcillin will decrease the level or effect of eszopiclone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ethinylestradiol

              nafcillin will decrease the level or effect of ethinylestradiol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ethosuximide

              nafcillin will decrease the level or effect of ethosuximide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • etoposide

              nafcillin will decrease the level or effect of etoposide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • etravirine

              nafcillin will decrease the level or effect of etravirine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • exemestane

              nafcillin will decrease the level or effect of exemestane by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • felbamate

              nafcillin will decrease the level or effect of felbamate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fentanyl

              nafcillin will decrease the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with CYP3A4 inducers could lead to a decrease in fentanyl plasma concentrations, lack of efficacy or, possibly, development of a withdrawal syndrome in a patient who has developed physical dependence to fentanyl. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the fentanyl plasma concentration will increase which could increase or prolong both the therapeutic and adverse effects.

            • fentanyl intranasal

              nafcillin will decrease the level or effect of fentanyl intranasal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with CYP3A4 inducers could lead to a decrease in fentanyl plasma concentrations, lack of efficacy or, possibly, development of a withdrawal syndrome in a patient who has developed physical dependence to fentanyl. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the fentanyl plasma concentration will increase which could increase or prolong both the therapeutic and adverse effects.

            • fentanyl transdermal

              nafcillin will decrease the level or effect of fentanyl transdermal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with CYP3A4 inducers could lead to a decrease in fentanyl plasma concentrations, lack of efficacy or, possibly, development of a withdrawal syndrome in a patient who has developed physical dependence to fentanyl. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the fentanyl plasma concentration will increase which could increase or prolong both the therapeutic and adverse effects.

            • fentanyl transmucosal

              nafcillin will decrease the level or effect of fentanyl transmucosal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of fentanyl with CYP3A4 inducers could lead to a decrease in fentanyl plasma concentrations, lack of efficacy or, possibly, development of a withdrawal syndrome in a patient who has developed physical dependence to fentanyl. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the fentanyl plasma concentration will increase which could increase or prolong both the therapeutic and adverse effects.

            • fesoterodine

              nafcillin will decrease the level or effect of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • flibanserin

              nafcillin will decrease the level or effect of flibanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers substantially decrease flibanserin systemic exposure.

            • flurazepam

              nafcillin will decrease the level or effect of flurazepam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • fosamprenavir

              nafcillin will decrease the level or effect of fosamprenavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • gefitinib

              nafcillin will decrease the level or effect of gefitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase gefitinib to 500 mg daily if coadministered with a strong CYP3A4 inducer. Resume gefitinib dose at 250 mg/day 7 days after discontinuing the strong inducer.

            • glecaprevir/pibrentasvir

              nafcillin will decrease the level or effect of glecaprevir/pibrentasvir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration of drugs that induce CYP3A4 with glecaprevir/pibrentasvir may decrease glecaprevir/pibrentasvir plasma concentrations. Potential for loss of therapeutic effect.

            • guanfacine

              nafcillin will decrease the level or effect of guanfacine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Strong or moderate CYP3A4 inducers significantly reduce guanfacine plasma concentrations and elimination half-life. If coadministered, more frequent dosing of the IR product may be required to achieve or maintain the desired hypotensive response. For patients with ADHD, FDA-approved labeling for ER guanfacine recommends that, if coadministered, doubling the recommended dose of guanfacine should be considered.

            • haloperidol

              nafcillin will decrease the level or effect of haloperidol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • hydrochlorothiazide

              nafcillin, hydrochlorothiazide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

            • hydrocodone

              nafcillin will decrease the level or effect of hydrocodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Caution when discontinuing CYP3A4 inducers that are coadministered with hydrocodone; plasma concentrations of hydrocodone may increase and can result in potentially fatal respiratory depression

            • hydroxyprogesterone caproate

              nafcillin will decrease the level or effect of hydroxyprogesterone caproate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ibuprofen IV

              nafcillin, ibuprofen IV. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

              nafcillin, ibuprofen IV. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.

            • ifosfamide

              nafcillin increases toxicity of ifosfamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers may increase the metabolism of ifosfamide to its active alkylating metabolites. CYP3A4 inducers may increase the formation of the neurotoxic/nephrotoxic ifosfamide metabolite, chloroacetaldehyde. Closely monitor patients taking ifosfamide with CYP3A4 inducers for toxicities and consider dose adjustment.

            • indapamide

              nafcillin, indapamide. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

            • indinavir

              nafcillin will decrease the level or effect of indinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • isosorbide dinitrate

              nafcillin will decrease the level or effect of isosorbide dinitrate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • isosorbide mononitrate

              nafcillin will decrease the level or effect of isosorbide mononitrate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • isradipine

              nafcillin decreases levels of isradipine by increasing metabolism. Use Caution/Monitor.

            • ixabepilone

              nafcillin will decrease the level or effect of ixabepilone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lapatinib

              nafcillin will decrease the level or effect of lapatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • levamlodipine

              nafcillin will decrease the level or effect of levamlodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. No information is available on the quantitative effects of CYP3A4 inducers on amlodipine. Closely monitor blood pressure when amlodipine is coadministered with CYP3A4 inducers.

            • levonorgestrel intrauterine

              nafcillin decreases levels of levonorgestrel intrauterine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • levonorgestrel oral

              nafcillin decreases levels of levonorgestrel oral by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • levonorgestrel oral/ethinylestradiol/ferrous bisglycinate

              nafcillin will decrease the level or effect of levonorgestrel oral/ethinylestradiol/ferrous bisglycinate by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. The efficacy of hormonal contraceptives may be reduced. Use an alternative method of contraception or a backup method when enzyme inducers are used with combined hormonal contraceptives (CHCs), and continue backup contraception for 28 days after discontinuing enzyme inducer to ensure contraceptive reliability.

            • linagliptin

              nafcillin will decrease the level or effect of linagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Use of alternative treatments is strongly recommended when linagliptin is to be administered with a CYP3A4 inducer.

            • lomitapide

              nafcillin will decrease the level or effect of lomitapide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • losartan

              nafcillin will decrease the level or effect of losartan by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • lurasidone

              nafcillin decreases levels of lurasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. It may be necessary to increase the lurasidone dose after chronic treatment (ie, 7 days or more) with moderate CYP3A inducers.

            • maraviroc

              nafcillin will decrease the level or effect of maraviroc by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • marijuana

              nafcillin will decrease the level or effect of marijuana by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • medroxyprogesterone

              nafcillin will decrease the level or effect of medroxyprogesterone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Contraceptirve failure possible. Use alternative if available.

            • mefloquine

              nafcillin will decrease the level or effect of mefloquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • mestranol

              nafcillin will decrease the level or effect of mestranol by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

              nafcillin will decrease the level or effect of mestranol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • methadone

              nafcillin will decrease the level or effect of methadone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • methotrexate

              nafcillin increases levels of methotrexate by decreasing renal clearance. Use Caution/Monitor. Increased serum concentrations of methotrexate with concomitant hematologic and gastrointestinal toxicity have been observed with concurrent administration of high or low doses of methotrexate and penicillins.

            • midazolam

              nafcillin will decrease the level or effect of midazolam by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • mifepristone

              nafcillin will decrease the level or effect of mifepristone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers have not been studied, coadministration not recommended by manufacturer

            • naldemedine

              nafcillin will decrease the level or effect of naldemedine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Simulation using physiologically-based pharmacokinetic modeling suggests that concomitant use of moderated CYP3A4 inducers decrease exposure to naldemedine. The clinical consequence of this decreased exposure is unknown.

            • nefazodone

              nafcillin will decrease the level or effect of nefazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nelfinavir

              nafcillin will decrease the level or effect of nelfinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nevirapine

              nafcillin will decrease the level or effect of nevirapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nicardipine

              nafcillin will decrease the level or effect of nicardipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              nafcillin decreases levels of nicardipine by increasing metabolism. Use Caution/Monitor.

            • nifedipine

              nafcillin will decrease the level or effect of nifedipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • nilotinib

              nafcillin will decrease the level or effect of nilotinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • nisoldipine

              nafcillin will decrease the level or effect of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              nafcillin decreases levels of nisoldipine by increasing metabolism. Use Caution/Monitor.

            • norethindrone

              nafcillin will decrease the level or effect of norethindrone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Use of nonhormonal contraceptives advised while in therapy

            • norgestrel

              nafcillin will decrease the level or effect of norgestrel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Use of nonhormonal contraceptives advised while in therapy

            • oliceridine

              nafcillin will decrease the level or effect of oliceridine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. If coadministration with a CYP3A4 inducer is necessary, consider increasing oliceridine dose until stable drug effects are achieved; monitor for signs of opioid withdrawal. If inducer is discontinued, consider oliceridine dosage reduction and monitor for signs of respiratory depression.

            • osilodrostat

              nafcillin will decrease the level or effect of osilodrostat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Monitor cortisol concentration and patient?s signs and symptoms during coadministration or discontinuation with strong CYP3A4 inducers. Adjust dose of osilodrostat if necessary.

            • oxycodone

              nafcillin decreases levels of oxycodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • palbociclib

              nafcillin will decrease the level or effect of palbociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • pazopanib

              nafcillin will decrease the level or effect of pazopanib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • pimavanserin

              nafcillin will decrease the level or effect of pimavanserin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Avoid coadministration if possible. Monitor for reduced pimavanserin efficacy. An increase in pimavanserin dosage may be needed.

            • pitolisant

              nafcillin will decrease the level or effect of pitolisant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Pitolisant exposure is decreased by 50% if coadministered with strong CYP3A4 inducers. For patients stable on pitolisant 8.9 mg/day or 17.8 mg/day, double the pitolisant dose (ie, 17.8 mg or 35.6 mg, respectively) over 7 days. If the strong CYP3A4 inducer is discontinued, reduce pitolisant dosage by half.

            • polatuzumab vedotin

              nafcillin will decrease the level or effect of polatuzumab vedotin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Polatuzumab undergoes catabolism to small peptides, amino acids, monomethyl auristatin E (MMAE), and unconjugated MMAE-related catabolites. MMAE is a CYP3A4 substrate. Coadministration of polatuzumab vedotin with a strong CYP3A4 inducer may decrease unconjugated MMAE AUC.

            • primaquine

              nafcillin will decrease the level or effect of primaquine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • probenecid

              probenecid will increase the level or effect of nafcillin by decreasing renal clearance. Use Caution/Monitor.

            • progesterone intravaginal gel

              nafcillin will decrease the level or effect of progesterone intravaginal gel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • progesterone micronized

              nafcillin will decrease the level or effect of progesterone micronized by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • progesterone, natural

              nafcillin will decrease the level or effect of progesterone, natural by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • quetiapine

              nafcillin will decrease the level or effect of quetiapine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • quinidine

              nafcillin will decrease the level or effect of quinidine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • repaglinide

              nafcillin will decrease the level or effect of repaglinide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ribociclib

              nafcillin will decrease the level or effect of ribociclib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rifabutin

              nafcillin will decrease the level or effect of rifabutin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rifampin

              nafcillin decreases effects of rifampin by pharmacodynamic antagonism. Use Caution/Monitor. Nafcillin may show antagonistic effects against S. aureus.

            • riociguat

              nafcillin will decrease the level or effect of riociguat by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Data not available for dose adjustment

            • ritonavir

              nafcillin will decrease the level or effect of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rivaroxaban

              nafcillin will decrease the level or effect of rivaroxaban by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • rose hips

              nafcillin, rose hips. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

            • ruxolitinib

              nafcillin will decrease the level or effect of ruxolitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • salicylates (non-asa)

              nafcillin, salicylates (non-asa). Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.

            • salsalate

              nafcillin, salsalate. Either increases levels of the other by plasma protein binding competition. Use Caution/Monitor.

            • saquinavir

              nafcillin will decrease the level or effect of saquinavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • sodium phenylacetate

              nafcillin, sodium phenylacetate. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

            • sodium picosulfate/magnesium oxide/anhydrous citric acid

              nafcillin decreases effects of sodium picosulfate/magnesium oxide/anhydrous citric acid by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug.

            • solifenacin

              nafcillin will decrease the level or effect of solifenacin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • sorafenib

              nafcillin decreases levels of sorafenib by increasing metabolism. Use Caution/Monitor.

            • sufentanil SL

              nafcillin decreases effects of sufentanil SL by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Coadministration of CYP3A4 inducers may decrease sufentanil levels and efficacy, possibly precipitating withdrawal syndrome in patients who have developed physical dependence to sufentanil. Discontinuation of concomitantly used CYP3A4 inducers may increase sufentanil plasma concentration.

            • sulfasalazine

              sulfasalazine decreases effects of nafcillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

            • sunitinib

              nafcillin will decrease the level or effect of sunitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • suvorexant

              nafcillin will decrease the level or effect of suvorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Strong CYP3A4 inducers may decrease suvorexant efficacy; if increased suvorexant dose required, do not exceed 20 mg/day

            • tacrolimus

              nafcillin will decrease the level or effect of tacrolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tadalafil

              nafcillin will decrease the level or effect of tadalafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tamoxifen

              nafcillin will decrease the level or effect of tamoxifen by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tamsulosin

              nafcillin will decrease the level or effect of tamsulosin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • temsirolimus

              nafcillin will decrease the level or effect of temsirolimus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • teniposide

              nafcillin will decrease the level or effect of teniposide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • terbinafine

              nafcillin will decrease the level or effect of terbinafine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tetracycline

              nafcillin will decrease the level or effect of tetracycline by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tiagabine

              nafcillin will decrease the level or effect of tiagabine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ticagrelor

              nafcillin will decrease the level or effect of ticagrelor by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tinidazole

              nafcillin will decrease the level or effect of tinidazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tipranavir

              nafcillin will decrease the level or effect of tipranavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • tofacitinib

              nafcillin will decrease the level or effect of tofacitinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Loss of, or decreased response to tofacitinib may occur when coadministered with potent CYP3A4 inducers

            • tolterodine

              nafcillin will decrease the level or effect of tolterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • toremifene

              nafcillin decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. CYP3A4 inducers increase rate of toremifene metabolism, lowering the steady-state concentration in serum.

            • tramadol

              nafcillin will decrease the level or effect of tramadol by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Decreased AUC of tramadol and the active metabolite (O-desmethyltramadol) when coadministered with strong CYP3A4 and CYP2B6 inducers

            • trazodone

              nafcillin will decrease the level or effect of trazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • ulipristal

              nafcillin will decrease the level or effect of ulipristal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • valbenazine

              nafcillin will decrease the level or effect of valbenazine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • vemurafenib

              nafcillin will decrease the level or effect of vemurafenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • verapamil

              nafcillin will decrease the level or effect of verapamil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

              nafcillin decreases levels of verapamil by increasing metabolism. Use Caution/Monitor.

            • vilazodone

              nafcillin decreases levels of vilazodone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Consider increasing vilazodone dose up to 2-fold (not to exceed 80 mg/day) when coadministered with strong CYP3A4 inducers for >14 days.

            • voriconazole

              nafcillin will decrease the level or effect of voriconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.

            • vortioxetine

              nafcillin decreases levels of vortioxetine by increasing metabolism. Modify Therapy/Monitor Closely. Consider increasing the vortioxetine dose when coadministered with strong CYP inducers for >14 days; not to exceed 3 times original vortioxetine dose.

              nafcillin will decrease the level or effect of vortioxetine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.

            • willow bark

              nafcillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

            Minor (31)

            • azithromycin

              azithromycin decreases effects of nafcillin by pharmacodynamic antagonism. Minor/Significance Unknown. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • chlorothiazide

              chlorothiazide increases levels of nafcillin by decreasing renal clearance. Minor/Significance Unknown.

            • clarithromycin

              clarithromycin decreases effects of nafcillin by pharmacodynamic antagonism. Minor/Significance Unknown. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • erythromycin base

              erythromycin base decreases effects of nafcillin by pharmacodynamic antagonism. Minor/Significance Unknown. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • erythromycin ethylsuccinate

              erythromycin ethylsuccinate decreases effects of nafcillin by pharmacodynamic antagonism. Minor/Significance Unknown. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • erythromycin lactobionate

              erythromycin lactobionate decreases effects of nafcillin by pharmacodynamic antagonism. Minor/Significance Unknown. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • erythromycin stearate

              erythromycin stearate decreases effects of nafcillin by pharmacodynamic antagonism. Minor/Significance Unknown. bacteriostatic antibiotics may interfere with the bactericidal actions of penicillins.

            • eucalyptus

              nafcillin will decrease the level or effect of eucalyptus by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • imatinib

              nafcillin will decrease the level or effect of imatinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • isradipine

              nafcillin will decrease the level or effect of isradipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • itraconazole

              nafcillin will decrease the level or effect of itraconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ketoconazole

              nafcillin will decrease the level or effect of ketoconazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • lansoprazole

              nafcillin will decrease the level or effect of lansoprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • methyclothiazide

              methyclothiazide increases levels of nafcillin by decreasing renal clearance. Minor/Significance Unknown.

            • nimodipine

              nafcillin will decrease the level or effect of nimodipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • nitrendipine

              nafcillin will decrease the level or effect of nitrendipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ondansetron

              nafcillin will decrease the level or effect of ondansetron by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • paclitaxel

              nafcillin will decrease the level or effect of paclitaxel by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • paclitaxel protein bound

              nafcillin will decrease the level or effect of paclitaxel protein bound by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • pimozide

              nafcillin will decrease the level or effect of pimozide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • quinine

              nafcillin will decrease the level or effect of quinine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • rabeprazole

              nafcillin will decrease the level or effect of rabeprazole by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • saxagliptin

              nafcillin will decrease the level or effect of saxagliptin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • thiamine

              nafcillin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

            • vinblastine

              nafcillin will decrease the level or effect of vinblastine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vincristine

              nafcillin will decrease the level or effect of vincristine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vincristine liposomal

              nafcillin will decrease the level or effect of vincristine liposomal by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • vinorelbine

              nafcillin will decrease the level or effect of vinorelbine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • ziprasidone

              nafcillin will decrease the level or effect of ziprasidone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zolpidem

              nafcillin will decrease the level or effect of zolpidem by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

            • zonisamide

              nafcillin will decrease the level or effect of zonisamide by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.

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            Adverse Effects

            1-10%

            Hypersensitivity

            Neutropenia

            Interstitial nephritis

            Possible hypokalemia

            <1%

            Neurotoxicity (high doses)

            Pseudomembranous colitis

            Phlebitis (oxacillin preferred in peds)

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            Warnings

            Contraindications

            A history of a hypersensitivity (anaphylactic) reaction to any penicillin

            Solutions containing dextrose in patients with known allergy to corn or corn products

            Cautions

            Evaluate renal, hepatic, hematologic systems periodically during prolonged treatment

            Serious and occasionally fatal hypersensitivity (anaphylactic) reactions reported; reactions are more likely to occur in individuals with history of penicillin hypersensitivity and/or a history of sensitivity to multiple allergens; inquire about previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens before initiating therapy; if allergic reaction occurs, discontinue treatment and institute appropriate therapy

            If clostridium difficile associated diarrhea (CDAD) suspected or confirmed, may need to discontinue ongoing antibiotic use not directed against C. difficile; appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated

            The use of antibiotics may result in overgrowth of nonsusceptible organisms; if new infections due to bacteria or fungi occur, discontinue drug and take appropriate measures

            To optimize therapy, determine causative organisms and susceptibility; > 10 d treatment to eliminate infection and prevent sequelae (eg, endocarditis, rheumatic fever); take cultures after treatment to confirm that infection is eradicated

            Elevation of liver transaminases and/or cholestasis may occur, specifically with administration of high doses

            Urinalysis, serum blood urea nitrogen, and creatinine determinations should be performed at baseline and periodically during therapy; serum bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, and gamma glutamyl transferase should be obtained at baseline and periodically during therapy, especially when using high nafcillin doses; in patients with worsening hepatic

            Renal tubular damage and interstitial nephritis associated with administration of nafcillin; manifestations of nephrotoxicity are hematuria, proteinuria, and acute kidney injury, and may be associated with rash, fever, and eosinophilia; majority of cases resolve upon discontinuation of nafcillin; some patients, may require dialysis treatment and may develop permanent renal damage

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            Pregnancy & Lactation

            Pregnancy Category: B

            Lactation: Excreted into breast milk; use caution

            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.

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            Pharmacology

            Mechanism of Action

            Inhibit synthesis of bacterial cell wall synthesis, which results in bactericidal activity

            Pharmacokinetics

            Half-Life: 0.5-1.5 hr (adults); 0.75-1.9 hr (children)

            Peak Plasma Time: 0.5-1 hr

            Protein binding: 90%

            Absorption: Poorly absorbed orally

            Distribution: In fluid, bone, bile, crosses placenta

            Vd: 0.5-1.5 L/kg

            Metabolism: Liver

            Excretion: Liver (primarily), renal (10-30%)

            Enzymes induced: Hepatic CYP3A4

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            Administration

            IV Incompatibilities

            Additive: aminophylline(?), ascorbic acid, aztreonam, bleomycin, cytarabine, gentamicin, hydrocortisone sodium succinate, methylprednisolone sodium succinate, promazine, vit B/C(?)

            Y-site: diltiazem(?), droperidol, insulin (regular), labetalol, meperidine(?), midazolam, nalbuphine, pentazocine, vancomycin(?), verapamil

            IV Compatibilities

            Solution: compatible w/ most common solvents

            Additive (partial list): dexamethasone sodium phosphate, diphenhydramine, heparin, lidocaine, KCl, prochlorperazine, Na bicarb

            Syringe: cimetidine, heparin

            Y-site (partial list): acyclovir, atropine, diazepam, fentanyl, fluconazole, heparin, MgSO4, morphine, propofol, zidovudine

            IV/IM Preparation

            IM/IV: reconstitute 1-2 g of drug w/ 3.4- 6.8 mL SWI/BWI/NS to 250 mg/mL

            IV inj: further dilute w/ 15-30 mL SWI/NS

            IV infusion: further dilute w/ IV solution according to Mfr's directions

            Bulk Packages:

            • Reconstitute 10 g of drug w/ 93 mL SWI/NS to 100 mg/mL
            • THEN further dilute before administration
            • Not for direct IV injection

            IV/IM Administration

            IM: deep into large muscle

            IV inj: slowly over 5-10 min

            IV infusion: over at least 30-60 min

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            Images

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            Copyright © 2010 First DataBank, Inc.

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            Patient Handout

            Select a drug:
            Patient Education
            nafcillin intravenous

            NAFCILLIN - INJECTION

            (naff-SIL-in)

            COMMON BRAND NAME(S): Unipen

            USES: This medication is used to treat a wide variety of bacterial infections. This medication is known as a penicillin-type antibiotic. It works by stopping the growth of bacteria.

            HOW TO USE: This medication is given by injection into a vein as directed by your doctor, usually every 4 to 6 hours. The dosage is based on your medical condition and response to therapy. For children, the dosage is also based on weight.If you are giving this medication to yourself at home, learn all preparation and usage instructions from your health care professional. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.Give aminoglycosides (such as gentamicin) separately from this medication. Do not mix together in the same IV fluid.For the best effect, use this antibiotic at evenly spaced times. To help you remember, use this medication at the same time(s) every day.Continue to use this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may allow bacteria to continue to grow, which may result in a return of the infection.Tell your doctor if your condition persists or worsens.

            SIDE EFFECTS: If this medication is injected into a muscle, pain at the injection site may occur. If this effect persists or worsens, notify your doctor or pharmacist promptly.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: pain/swelling/skin peeling at injection site (if this drug is injected into a vein), joint/muscle pain, signs of kidney problems (such as change in the amount of urine, pink/bloody/frothy/dark/cloudy urine), extreme tiredness, easy bruising/bleeding, new signs of infection (e.g., fever, persistent sore throat), seizures, uncontrolled movements, confusion, irregular heartbeat, muscle cramps, weakness.This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop: diarrhea that doesn't stop, abdominal or stomach pain/cramping, blood/mucus in your stool.If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.Use of this medication for prolonged or repeated periods may result in oral thrush or a new vaginal yeast infection. Contact your doctor if you notice white patches in your mouth, a change in vaginal discharge, or other new symptoms.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 using this medication, tell your doctor or pharmacist if you are allergic to it; or to penicillin or cephalosporin antibiotics; or if you have any other allergies. This product may contain inactive ingredients (such as corn for products containing dextrose), 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: asthma, kidney disease, liver disease.This medication contains sodium. This could affect you if you are on a salt-restricted diet or if you have a condition which could be worsened with an increase in salt intake (e.g., congestive heart failure). Consult your doctor or pharmacist for more information.Nafcillin may cause live bacterial vaccines (such as typhoid vaccine) to not work as well. Do not have any immunizations/vaccinations while using this medication unless your doctor tells you to.Liver and kidney functions decline as you grow older. This medication is removed by the liver. Elderly people may be at greater risk for side effects while using this drug.Liver and kidney functions are not fully developed in newborns and infants. This medication is removed by the liver. Newborns and infants may be a greater risk for side effects while using this drug.During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.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: "blood thinners" (e.g., warfarin), methotrexate, tetracyclines.This medication can speed up the removal of other medications from your body, which may affect how they work. Examples of affected drugs include certain products used to treat chronic hepatitis C (asunaprevir, ombitasvir/paritaprevir/ritonavir), among others.This medication may interfere with certain laboratory tests (including certain urine protein tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.

            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. Symptoms of overdose may include: seizures, confusion, mental/mood changes (e.g., agitation).

            NOTES: Laboratory and/or medical tests (e.g., kidney/liver function, complete blood count) may be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

            MISSED DOSE: It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule. Do not double the dose to catch up.

            STORAGE: Consult the product instructions and your pharmacist for storage details. 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.

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            Formulary

            FormularyPatient Discounts

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

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            • View the formulary and any restrictions for each plan.
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            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
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.