Dosing & Uses
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
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (20)
- 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
- mavacamten
nafcillin will decrease the level or effect of mavacamten by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
- 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 (DSC)
nafcillin will decrease the level or effect of ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Strong CYP3A4 inducers may reduce partiaprevir and ritonavir levels, and therefore decreased efficacy of Viekira Pak
- pacritinib
nafcillin will decrease the level or effect of pacritinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated.
- 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 (116)
- 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.
- daridorexant
nafcillin will decrease the level or effect of daridorexant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- 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.
- elacestrant
nafcillin will decrease the level or effect of elacestrant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- 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.
- ganaxolone
nafcillin will decrease the level or effect of ganaxolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of ganaxolone with moderate or strong CYP3A4 inducers. If coadministration unavoidable, consider increasing ganaxolone dose; however, do not exceed maximum daily dose for weight.
- 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.
- leniolisib
nafcillin will decrease the level or effect of leniolisib 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.
- lumateperone
nafcillin will decrease the level or effect of lumateperone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- 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
- microbiota oral
nafcillin decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .
- 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
- olutasidenib
nafcillin will decrease the level or effect of olutasidenib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Strong or moderate CYP3A inducers decrease olutasidenib (a CYP3A4 substrate) plasma concentrations and efficacy.
- 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.
- omaveloxolone
nafcillin will decrease the level or effect of omaveloxolone by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- 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.
- palovarotene
nafcillin will decrease the level or effect of palovarotene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- 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.
- pirtobrutinib
nafcillin will decrease the level or effect of pirtobrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. If coadministration unavoidable, increase pirtobrutinib dose to 300 mg qDay (if dose is 200 mg qDay) or increase pirtobrutinib dose by 50 mg (if current pirtobrutinib dose is 50 mg or 100 mg qDay).
- 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.
- quizartinib
nafcillin will decrease the level or effect of quizartinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. 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.
- 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.
- vonoprazan
nafcillin will decrease the level or effect of vonoprazan 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.
- zanubrutinib
nafcillin will decrease the level or effect of zanubrutinib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of zanubrutinib (a CYP3A4 substrate) with moderate CYP3A4 inhibitors. If unavoidable, increase zanubrutinib dose to 320 mg PO BID. After discontinuing the CYP3A4 inhibitor, resume previous dose of zanubrutinib.
Monitor Closely (170)
- 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. - atogepant
nafcillin will decrease the level or effect of atogepant by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Recommended atogepant dosage with concomitant use of strong or moderate CYP3A4 inducers is 30 mg or 60 mg qDay.
- 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. - belumosudil
nafcillin will decrease the level or effect of belumosudil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase belumosudil dosage to 200 mg PO BID when coadministered with strong CYP3A inducers.
- 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 (DSC)
nafcillin will decrease the level or effect of hydroxyprogesterone caproate (DSC) 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. Modify Therapy/Monitor Closely. Moderate CYP3A4 inducers may decrease progestin concentration; consider use of additional barrier methods
- 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.
- ruxolitinib topical
nafcillin will decrease the level or effect of ruxolitinib topical 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. - warfarin
nafcillin will decrease the level or effect of warfarin by Other (see comment). Use Caution/Monitor. Warfarin's less potent R-enantiomer is metabolized in part by CYP3A4 (and also CYP1A2 and CYP2C19). Monitor INR more frequently if coadministered with inducers of these isoenzymes and adjust warfarin dose if needed.
- willow bark
nafcillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.
Minor (32)
- 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.
- levoketoconazole
nafcillin will decrease the level or effect of levoketoconazole 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.
Adverse Effects
1-10%
Hypersensitivity
Neutropenia
Interstitial nephritis
Possible hypokalemia
<1%
Neurotoxicity (high doses)
Pseudomembranous colitis
Phlebitis (oxacillin preferred in peds)
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
Use with caution in patients with histories of significant allergies and/or asthma; whenever allergic reactions occur, withdraw penicillin unless, in the opinion of the physician, the condition being treated is life-threatening and amenable only to penicillin therapy
Liver/biliary tract is primary route of nafcillin clearance; exercise caution when patients with concomitant hepatic insufficiency and renal dysfunction are treated with this drug
Prescribing the antibiotic in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to patient and increases risk of development of drug-resistant bacteria
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
Clostridium difficile
- C. difficile produces toxins A and B which contribute to development of CDAD;hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy
- CDAD must be considered in all patients who present with diarrhea following antibiotic use; careful medical history necessary since CDAD has been reported to occur over two months after administration of antibacterial agents
- 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
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.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
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
Images
BRAND | FORM. | UNIT PRICE | PILL IMAGE |
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nafcillin intravenous - | 2 gram vial | ![]() | |
nafcillin intravenous - | 1 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() | |
nafcillin injection - | 10 gram vial | ![]() | |
nafcillin injection - | 2 gram vial | ![]() | |
nafcillin injection - | 1 gram vial | ![]() |
Copyright © 2010 First DataBank, Inc.
Patient Handout
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 lasts or gets worse.
SIDE EFFECTS: If this medication is injected into a muscle, pain at the injection site may occur. If this effect lasts or gets worse, 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 (such as sore throat that doesn't go away, fever), 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 (such as congestive heart failure). Consult your doctor or pharmacist for more information.Nafcillin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using nafcillin before having any immunizations/vaccinations.Older adults 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" (such as 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 daridorexant, elacestrant, certain products used to treat chronic hepatitis C (asunaprevir, ombitasvir/paritaprevir/ritonavir), quizartinib, among others.This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use reliable backup birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.This medication may interfere with certain lab tests (such as urine protein tests), possibly causing false test results. Make sure lab 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 (such as agitation).
NOTES: Lab and/or medical tests (such as kidney/liver function, complete blood count) may be done while you are using this medication. Keep all medical and lab appointments. 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 2023. Copyright(c) 2023 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.
Formulary
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