Version July 2025
Usual dosage range: IV: 1 to 2 g every 4 to 6 hours; may also administer total daily dose as a continuous infusion over 24 hours (eg, for a dose of 2 g every 4 hours, administer 12 g over 24 hours) (Ref).
Bloodstream infection: Pathogen-directed therapy for methicillin-susceptible staphylococci: IV: 2 g every 4 hours; treat uncomplicated bacteremia for ≥14 days starting from day of first negative blood culture, with longer courses warranted for endocarditis or metastatic sites of infection (Ref).
Endocarditis, treatment: Pathogen-directed therapy for methicillin-susceptible staphylococci:
Native valve: IV: 12 g/day in 4 or 6 divided doses (ie, 2 g every 4 hours or 3 g every 6 hours) for 6 weeks. For uncomplicated right-sided IE, 2 weeks of therapy may be adequate (Ref).
Prosthetic valve: IV: 12 g/day in 6 divided doses (ie, 2 g every 4 hours) for ≥6 weeks (use with rifampin for entire duration of therapy and gentamicin for first 2 weeks) (Ref).
Meningitis, bacterial: Pathogen-directed therapy for methicillin-susceptible staphylococci : IV: 2 g every 4 hours; consider addition of rifampin if organism is susceptible and prosthetic material is present. Treatment duration is 10 to 14 days, depending on causative pathogen(s) and clinical response (Ref).
Osteomyelitis and/or discitis: Pathogen-directed therapy for methicillin-susceptible staphylococci: IV: 1.5 to 2 g every 4 to 6 hours or via continuous infusion for ≥6 weeks depending on extent of infection, debridement, and clinical response (Ref).
Pneumonia: Pathogen-directed therapy for methicillin-susceptible staphylococci : IV: 2 g every 4 hours (Ref). Minimum duration is generally 5 days for community-acquired pneumonia and 7 days for hospital-acquired or ventilator-associated pneumonia; patients should be clinically stable with normal vital signs before therapy is discontinued (Ref).
Prosthetic joint infection: Pathogen-directed therapy for methicillin-susceptible staphylococci: IV: 1.5 to 2 g every 4 to 6 hours; duration ranges from 2 to 6 weeks depending on prosthesis management, use of rifampin, and other patient-specific factors (Ref).
Skin and soft tissue infection:
Cellulitis (nonpurulent) in patients without risk for methicillin-resistant S. aureus: IV: 1 to 2 g every 4 hours. Total duration of therapy is ≥5 days (including oral step-down therapy); may extend up to 14 days depending on severity and clinical response (Ref).
Necrotizing infection due to methicillin-susceptible S. aureus (MSSA): IV: 1 to 2 g every 4 hours; continue until further debridement is not necessary, patient has clinically improved, and patient is afebrile for 48 to 72 hours (Ref).
Surgical site incisional infection (trunk or extremity, not involving axilla or perineum): IV: 2 g every 6 hours; duration is dependent upon severity, need for debridement, and clinical response (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason A. Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Note: In one retrospective review of patients receiving continuous nafcillin infusions, increased SCr was associated with decreased nafcillin clearance; increased nafcillin concentrations were associated with increased incidence of adverse drug reactions (hepatotoxicity, nausea/vomiting, and diarrhea) (Ref); periodically assess for tolerability (Ref).
Altered kidney function: No dosage adjustment necessary for any degree of kidney impairment (Ref).
Hemodialysis, intermittent (thrice weekly): Not significantly dialyzable (Ref): No supplemental dose or dosage adjustment necessary (Ref).
Peritoneal dialysis: Unlikely to be significantly dialyzable (highly protein bound): No dosage adjustment necessary (Ref).
CRRT: No dosage adjustment necessary (Ref).
PIRRT (eg, sustained, low-efficiency diafiltration): No dosage adjustment necessary (Ref).
There are no dosage adjustments provided in the manufacturer's labeling. Nafcillin primarily undergoes hepatic metabolism; dosage adjustment may be necessary, particularly in the setting of concomitant renal impairment.
Refer to adult dosing.
(For additional information see "Nafcillin: Pediatric drug information")
General dosing, susceptible infection:
Traditional (intermittent) dosing: Infants, Children, and Adolescents: IM, IV: 100 to 200 mg/kg/day in divided doses every 4 to 6 hours; maximum daily dose: 12 g/day divided every 4 hours; usual maximum dose: 2,000 mg/dose (Ref).
Continuous infusion dosing: Limited data available: Children and Adolescents: IV: 150 to 200 mg/kg/day infused continuously over 24 hours; maximum daily dose: 12 g/day. Dosing based on a retrospective case series in 40 pediatric patients (median age: 9 years; interquartile range: 2.3 to 12 years); the reported mean dose was 190 ± 36.4 mg/kg/day; the majority of infections treated were methicillin-susceptible Staphylococcus aureus (MSSA) (87.2% of patients) and coagulase negative staphylococcal species (7.7%); infection sites were primarily bloodstream, musculoskeletal, and skin and soft tissue (Ref).
Endocarditis, treatment (Ref): Children and Adolescents: IV: 200 mg/kg/day in divided doses every 4 to 6 hours; maximum daily dose: 12 g/day divided every 4 hours; treat for at least 4 weeks; longer durations may be necessary; may use in combination with gentamicin for some resistant organisms (Ref).
Meningitis, including health care–associated ventriculitis/meningitis; methicillin-susceptible Staphylococcus aureus: Infants, Children, and Adolescents: IV: 200 mg/kg/day in divided doses every 6 hours; maximum daily dose: 12 g/day; usual maximum dose: 2,000 mg/dose (Ref).
Osteoarticular infection, acute (eg, bacterial arthritis, osteomyelitis): Infants, Children, and Adolescents: IV: 100 to 200 mg/kg/day in divided doses every 4 to 6 hours; maximum daily dose: 12 g/day. Duration of therapy should be individualized based on several factors, including causative pathogen, response to therapy, and normalization of inflammatory markers. For acute hematogenous osteomyelitis, the minimum total duration is 3 to 4 weeks of therapy. For acute bacterial arthritis without osteomyelitis, typical duration is 3 to 4 weeks, but courses as short as 10 to 14 days may be considered in patients with adequate source control who improve rapidly with a consistent, progressive decrease in C-reactive protein by the end of the first week (Ref). Note: Prolonged or continuous infusion may be beneficial to maximize time above MIC (Ref).
Skin and soft tissue infection (Ref): Infants, Children, and Adolescents:
MSSA, non-necrotizing infection: IV: 100 to 150 mg/kg/day in divided doses every 6 hours; maximum daily dose: 12 g/day; usual maximum dose: 2,000 mg/dose.
MSSA, necrotizing infection: IV: 200 mg/kg/day in divided doses every 6 hours; maximum daily dose: 12 g/day; usual maximum dose: 2,000 mg/dose; continue until further debridement is not necessary, patient has clinically improved, and patient is afebrile for 48 to 72 hours.
Streptococcal skin infections: Infants, Children, and Adolescents: IV: 200 mg/kg/day in divided doses every 6 hours; maximum daily dose: 12 g/day; usual maximum dose: 2,000 mg/dose.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Infants, Children, and Adolescents: No dosage adjustment is necessary unless renal impairment is in the setting of concomitant hepatic impairment then use with caution; specific adjustment for combined renal and hepatic impairment is not provided in the manufacturer's labeling.
Poorly dialyzed; no supplemental dose or dosage adjustment necessary, including patients on intermittent hemodialysis, peritoneal dialysis, or continuous renal replacement therapy (eg, CVVHD) (Ref).
Infants, Children, and Adolescents: There are no dosage adjustments provided in the manufacturer's labeling; however, dosage adjustment may be necessary particularly in the setting of concomitant renal impairment; nafcillin primarily undergoes hepatic metabolism. In patients with both hepatic and renal impairment, monitoring of serum drug concentrations and modification of dosage may be necessary.
The following adverse drug reactions are derived from product labeling unless otherwise specified.
Postmarketing:
Dermatologic: Bullous rash (Chang 2012)
Gastrointestinal: Cholestasis (Guido 2017), Clostridioides difficile-associated diarrhea
Hematologic & oncologic: Agranulocytosis (Markowitz 1975), bone marrow depression, neutropenia (Chang 2012)
Hepatic: Cholestatic hepatitis (Guido 2017), increased serum transaminases (Guido 2017; Khatib 2021), jaundice (Guido 2017)
Hypersensitivity: Drug reaction with eosinophilia and systemic symptoms (Nguyen 2019), hypersensitivity angiitis (Xie 2015), hypersensitivity reaction (Blumenthal 2014)
Local: Inflammation at injection site, injection-site phlebitis, local desquamation (injection site), pain at injection site, swelling at injection site
Renal: Interstitial nephritis (Bodendorfer 1980), renal tubular disease
Hypersensitivity to nafcillin, other penicillins, or any component of the formulation.
Concerns related to adverse effects:
• Anaphylactic/hypersensitivity reactions: Serious and occasionally severe or fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy, especially with a history of beta-lactam hypersensitivity or a history of sensitivity to multiple allergens. Use with caution in patients with a history of significant allergies and/or asthma; discontinue treatment and institute appropriate therapy if an allergic reaction occurs.
• Extravasation: Vesicant; avoid extravasation of IV infusions; ensure proper catheter or needle position prior to and during infusion.
• Hepatic effects: Elevation of liver transaminases and/or cholestasis may occur, specifically with high doses. Reevaluate use in patients who develop worsening hepatic function.
• Hypokalemia: Hypokalemia has been observed in pediatric and adult patients. In a retrospective cohort study comparing tolerability of maximum daily dosing (12 g) of nafcillin and oxacillin in adults (n=224; median age: 56 years; range: 19 to 90 years), the observed incidences of hypokalemia (≤3.3 mmol/L), severe hypokalemia (≤2.9 mmol/L), and acute decreases (≥0.5 mmol/L) from baseline of serum potassium were significantly higher in the nafcillin group compared to oxacillin; median time to onset was 3 to 4 days (Viehman 2016). While a similar level of comparison has not been reported in pediatric patients, hypokalemia has been observed with nafcillin therapy in pediatric patients. In a study of children and adolescents receiving continuous infusion nafcillin at a mean dose of 190 ± 36.4 mg/kg/day, hypokalemia developed in 3 (7.5%) subjects (Knoderer 2017). Hypokalemia was also reported in a retrospective review of 30 pediatric patients with malignancies who received nafcillin in combination with carbenicillin and gentamicin; hypokalemia was reported in 50% (24/48) of antibiotic courses and usual reported onset was 4 days of therapy (Stapleton 1976).
• Neurotoxic effects: Large IV or intraventricular doses have been associated with neurotoxicity; use caution, especially in patients with concomitant renal and hepatic dysfunction.
• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.
Disease-related concerns:
• Heart failure: May contain a significant amount of sodium; use with caution in patients with heart failure.
• Hepatic/renal impairment: Use with caution in patients with concomitant hepatic and renal impairment.
Nafcillin seems to be better tolerated than oxacillin. In a study of pediatric patients (5 to 19 years) receiving outpatient nafcillin for >3 weeks, significantly less rash was reported in the nafcillin group (10.3%) compared to oxacillin group (31.7%). Hepatotoxicity was also higher in the oxacillin group (22% vs 0%) (Maraqa 2002).
Nafcillin lyophilized powder contains sodium approximately 66 mg [2.9 mEq] per gram of nafcillin.
Nafcillin in Dextrose (iso-osmotic) contains sodium 76.6 mg [3.33 mEq] per gram of nafcillin.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Solution, Intravenous:
Generic: 2 g/100 mL (100 mL)
Solution, Intravenous [preservative free]:
Generic: 1 g/50 mL (50 mL [DSC])
Solution Reconstituted, Injection:
Generic: 1 g (1 ea); 2 g (1 ea)
Solution Reconstituted, Injection [preservative free]:
Generic: 1 g (1 ea); 2 g (1 ea)
Solution Reconstituted, Intravenous:
Generic: 10 g (1 ea)
Solution Reconstituted, Intravenous [preservative free]:
Generic: 1 g (1 ea [DSC]); 2 g (1 ea [DSC]); 10 g (1 ea)
Yes
Solution (Nafcillin Sodium in Dextrose Intravenous)
2 g/100 mL (per mL): $0.29
Solution (reconstituted) (Nafcillin Sodium Injection)
1 g (per each): $11.40 - $17.87
2 g (per each): $7.55 - $34.67
Solution (reconstituted) (Nafcillin Sodium Intravenous)
10 g (per each): $78.00 - $174.00
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IM: Administer as a deep intragluteal injection; rotate injection sites.
IV: Infuse over 30 to 60 minutes; may administer as a direct injection over 5 to 10 minutes. Total daily dose may also be administered over 24 hours as a continuous infusion (Ref). Vesicant; ensure proper needle or catheter placement prior to and during IV infusion. Avoid extravasation.
Extravasation management: If extravasation occurs, stop infusion immediately; leave needle/cannula in place temporarily but do NOT flush the line; gently aspirate extravasated solution, then remove needle/cannula; elevate extremity; apply dry warm compresses; initiate hyaluronidase antidote (Ref).
Hyaluronidase: Intradermal or SUBQ: Inject a total of 1 mL (15 units/mL) as 5 separate 0.2 mL injections (using a tuberculin syringe) around the site of extravasation; if IV catheter remains in place, administer IV through the infiltrated catheter; may repeat in 30 to 60 minutes if no resolution (Ref).
Parenteral:
IM: Administer reconstituted solution as deep intragluteal injection per manufacturer's labeling; appropriate injection site should take into consideration patient age, muscle development, and volume of dose (Ref); only use intragluteal injection if appropriate; rotate injection sites.
IV:
Direct IV injection: Further dilute and administer over 5 to 10 minutes.
Intermittent IV infusion: Infuse over 30 to 60 minutes.
Continuous IV infusion: Children and Adolescents: Infuse daily dose over 24 hours (Ref).
Vesicant; ensure proper needle or catheter placement prior to and during IV infusion. Avoid extravasation. If extravasation occurs, stop infusion immediately; leave needle/cannula in place temporarily but do NOT flush the line; gently aspirate extravasated solution, then remove needle/cannula; elevate extremity; apply dry warm compresses; initiate hyaluronidase antidote (Ref).
Staphylococcal infections: Treatment of infections caused by susceptible penicillinase-producing staphylococci
Substrate of OAT1/3; Induces CYP3A4 (Moderate);
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Abemaciclib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Abemaciclib. Risk X: Avoid
Abiraterone Acetate: CYP3A4 Inducers (Moderate) may decrease serum concentration of Abiraterone Acetate. Risk C: Monitor
Acalabrutinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Acalabrutinib. Risk C: Monitor
Acemetacin: May increase serum concentration of Penicillins. Risk C: Monitor
ALfentanil: CYP3A4 Inducers (Moderate) may decrease serum concentration of ALfentanil. Management: If concomitant use of alfentanil and moderate CYP3A4 inducers is necessary, consider dosage increase of alfentanil until stable drug effects are achieved. Monitor patients for signs of opioid withdrawal. Risk D: Consider Therapy Modification
Alpelisib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Alpelisib. Risk C: Monitor
ALPRAZolam: CYP3A4 Inducers (Moderate) may decrease serum concentration of ALPRAZolam. Risk C: Monitor
Aminoglycosides: Penicillins may decrease serum concentration of Aminoglycosides. Primarily associated with extended spectrum penicillins, and patients with renal dysfunction. Risk C: Monitor
AmLODIPine: CYP3A4 Inducers (Moderate) may decrease serum concentration of AmLODIPine. Risk C: Monitor
Antihepaciviral Combination Products: CYP3A4 Inducers (Moderate) may decrease serum concentration of Antihepaciviral Combination Products. Risk X: Avoid
Apremilast: CYP3A4 Inducers (Moderate) may decrease serum concentration of Apremilast. Risk C: Monitor
Aprepitant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Aprepitant. Risk C: Monitor
ARIPiprazole Lauroxil: CYP3A4 Inducers (Moderate) may decrease serum concentration of ARIPiprazole Lauroxil. Risk C: Monitor
ARIPiprazole: CYP3A4 Inducers (Moderate) may decrease serum concentration of ARIPiprazole. Risk C: Monitor
Artemether and Lumefantrine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Artemether and Lumefantrine. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Artemether and Lumefantrine. Specifically, concentrations of dihydroartemisinin (DHA), the active metabolite of artemether may be decreased. Risk C: Monitor
Atazanavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Atazanavir. Risk C: Monitor
Atogepant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Atogepant. Management: For treatment of episodic migraine, the recommended dose of atogepant is 30 mg once daily or 60 mg once daily when combined with CYP3A4 inducers. When used for treatment of chronic migraine, use of atogepant with CYP3A4 inducers should be avoided. Risk D: Consider Therapy Modification
Atorvastatin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Atorvastatin. Risk C: Monitor
Atrasentan: CYP3A4 Inducers (Moderate) may decrease serum concentration of Atrasentan. Risk X: Avoid
Avacopan: CYP3A4 Inducers (Moderate) may decrease serum concentration of Avacopan. Risk X: Avoid
Avanafil: CYP3A4 Inducers (Moderate) may decrease serum concentration of Avanafil. Risk X: Avoid
Avapritinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Avapritinib. Risk X: Avoid
Axitinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Axitinib. Management: Concurrent use of axitinib with a moderate CYP3A4 inducer should be avoided when possible. If any such combination is necessary, monitor for reduced axitinib efficacy. Risk D: Consider Therapy Modification
Bacillus clausii: Antibiotics may decrease therapeutic effects of Bacillus clausii. Management: Bacillus clausii should be taken in between antibiotic doses during concomitant therapy. Risk D: Consider Therapy Modification
BCG (Intravesical): Antibiotics may decrease therapeutic effects of BCG (Intravesical). Risk X: Avoid
BCG Vaccine (Immunization): Antibiotics may decrease therapeutic effects of BCG Vaccine (Immunization). Risk C: Monitor
Bedaquiline: CYP3A4 Inducers (Moderate) may decrease serum concentration of Bedaquiline. CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Bedaquiline. Risk X: Avoid
Belumosudil: CYP3A4 Inducers (Moderate) may decrease serum concentration of Belumosudil. Risk C: Monitor
Benzhydrocodone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Benzhydrocodone. Specifically, the serum concentrations of hydrocodone may be reduced. Risk C: Monitor
Bortezomib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Bortezomib. Risk C: Monitor
Bosutinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Bosutinib. Risk C: Monitor
Brexpiprazole: CYP3A4 Inducers (Moderate) may decrease serum concentration of Brexpiprazole. Risk C: Monitor
Brigatinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Brigatinib. Management: Avoid concurrent use of brigatinib with moderate CYP3A4 inducers when possible. If combined, increase the daily dose of brigatinib in 30 mg increments after 7 days of treatment with the current brigatinib dose, up to maximum of twice the dose. Risk D: Consider Therapy Modification
Buprenorphine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Buprenorphine. Risk C: Monitor
BusPIRone: CYP3A4 Inducers (Moderate) may decrease serum concentration of BusPIRone. Risk C: Monitor
Cabozantinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Cabozantinib. Management: For cabozantinib tablets (Cabometyx), avoid combined use if possible. If combined, increase cabozantinib by 20 mg from previous dose, max 80 mg daily. For cabozantinib capsules (Cometriq), monitor for reduced cabozantinib efficacy if combined. Risk D: Consider Therapy Modification
Calcifediol: CYP3A4 Inducers (Moderate) may decrease serum concentration of Calcifediol. Risk C: Monitor
Calcitriol (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Calcitriol (Systemic). Risk C: Monitor
Cannabis: CYP3A4 Inducers (Moderate) may decrease serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be decreased. Risk C: Monitor
Capivasertib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Capivasertib. Risk X: Avoid
Capmatinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Capmatinib. Risk X: Avoid
CarBAMazepine: CYP3A4 Inducers (Moderate) may decrease serum concentration of CarBAMazepine. Risk C: Monitor
Cariprazine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Cariprazine. Risk X: Avoid
Ceritinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ceritinib. Risk C: Monitor
Cholera Vaccine: Antibiotics may decrease therapeutic effects of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Risk X: Avoid
Clarithromycin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Clarithromycin. CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Clarithromycin. Management: Consider alternative antimicrobial therapy for patients receiving a CYP3A4 inducer. Drugs that enhance the metabolism of clarithromycin into 14-hydroxyclarithromycin may alter the clinical activity of clarithromycin and impair its efficacy. Risk D: Consider Therapy Modification
Clindamycin (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Clindamycin (Systemic). Risk C: Monitor
CloZAPine: CYP3A4 Inducers (Moderate) may decrease serum concentration of CloZAPine. Risk C: Monitor
Cobicistat: CYP3A4 Inducers (Moderate) may decrease serum concentration of Cobicistat. Risk C: Monitor
Cobimetinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Cobimetinib. Risk X: Avoid
Codeine: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Codeine. Risk C: Monitor
Copanlisib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Copanlisib. Risk C: Monitor
Crinecerfont: CYP3A4 Inducers (Moderate) may decrease serum concentration of Crinecerfont. Management: Double the evening dose of crinecerfont and continue the morning dose unchanged during coadministration with moderate CYP3A4 inducers. See full interaction monograph for details. Risk D: Consider Therapy Modification
Crizotinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Crizotinib. Risk C: Monitor
CycloSPORINE (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of CycloSPORINE (Systemic). Risk C: Monitor
Daclatasvir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Daclatasvir. Management: Increase the daclatasvir dose to 90 mg once daily if used with a moderate CYP3A4 inducer. Risk D: Consider Therapy Modification
Dapsone (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Dapsone (Systemic). Risk C: Monitor
Daridorexant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Daridorexant. Risk X: Avoid
Dasabuvir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Dasabuvir. Risk X: Avoid
Dasatinib: CYP3A4 Inducers (Moderate) may increase serum concentration of Dasatinib. Risk C: Monitor
Deflazacort: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Deflazacort. Risk X: Avoid
DexAMETHasone (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of DexAMETHasone (Systemic). Risk C: Monitor
DiazePAM: CYP3A4 Inducers (Moderate) may decrease serum concentration of DiazePAM. Risk C: Monitor
Dichlorphenamide: Penicillins may increase hypokalemic effects of Dichlorphenamide. Risk C: Monitor
Dienogest: CYP3A4 Inducers (Moderate) may decrease serum concentration of Dienogest. Risk C: Monitor
DilTIAZem: CYP3A4 Inducers (Moderate) may decrease serum concentration of DilTIAZem. Risk C: Monitor
Disopyramide: CYP3A4 Inducers (Moderate) may decrease serum concentration of Disopyramide. Risk C: Monitor
Doravirine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Doravirine. Risk C: Monitor
DOXOrubicin (Conventional): CYP3A4 Inducers (Moderate) may decrease serum concentration of DOXOrubicin (Conventional). Risk X: Avoid
DroNABinol: CYP3A4 Inducers (Moderate) may decrease serum concentration of DroNABinol. Risk C: Monitor
Dronedarone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Dronedarone. Risk C: Monitor
Duvelisib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Duvelisib. Management: Avoid if possible. If used, on day 12 of combination increase duvelisib from 25 mg twice daily to 40 mg twice daily or from 15 mg twice daily to 25 mg twice daily. Resume prior duvelisib dose 14 days after stopping moderate CYP3A4 inducer. Risk D: Consider Therapy Modification
Dydrogesterone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Dydrogesterone. Risk C: Monitor
Efavirenz: CYP3A4 Inducers (Moderate) may decrease serum concentration of Efavirenz. Risk C: Monitor
Elacestrant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Elacestrant. Risk X: Avoid
Elbasvir and Grazoprevir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Elbasvir and Grazoprevir. Risk X: Avoid
Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Risk C: Monitor
Eliglustat: CYP3A4 Inducers (Moderate) may decrease serum concentration of Eliglustat. Risk C: Monitor
Encorafenib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Encorafenib. Risk C: Monitor
Ensartinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ensartinib. Risk X: Avoid
Entrectinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Entrectinib. Risk X: Avoid
Enzalutamide: CYP3A4 Inducers (Moderate) may decrease serum concentration of Enzalutamide. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Enzalutamide. Risk C: Monitor
Erdafitinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Erdafitinib. Management: If a moderate CYP3A4 inducer must be used at the start of erdafitinib, administer erdafitinib at a dose of 9 mg daily. If a moderate CYP3A4 inducer is discontinued, continue erdafitinib at the same dose unless there is evidence of drug toxicity. Risk D: Consider Therapy Modification
Erlotinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Erlotinib. Management: Avoid the combination of erlotinib and strong CYP3A4 inducers whenever possible. If this combination must be used, increase erlotinib dose by 50 mg increments every 2 weeks as tolerated, to a maximum of 450 mg/day. Risk D: Consider Therapy Modification
Estrogen Derivatives: CYP3A4 Inducers (Moderate) may decrease serum concentration of Estrogen Derivatives. Risk C: Monitor
Etoposide Phosphate: CYP3A4 Inducers (Moderate) may decrease serum concentration of Etoposide Phosphate. Risk C: Monitor
Etoposide: CYP3A4 Inducers (Moderate) may decrease serum concentration of Etoposide. Risk C: Monitor
Etravirine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Etravirine. Risk C: Monitor
Everolimus: CYP3A4 Inducers (Moderate) may decrease serum concentration of Everolimus. Risk C: Monitor
Exemestane: CYP3A4 Inducers (Moderate) may decrease serum concentration of Exemestane. Risk C: Monitor
Fecal Microbiota (Live) (Oral): May decrease therapeutic effects of Antibiotics. Risk X: Avoid
Fecal Microbiota (Live) (Rectal): Antibiotics may decrease therapeutic effects of Fecal Microbiota (Live) (Rectal). Risk X: Avoid
Fedratinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Fedratinib. Risk X: Avoid
Felodipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Felodipine. Risk C: Monitor
FentaNYL: CYP3A4 Inducers (Moderate) may decrease serum concentration of FentaNYL. Risk C: Monitor
Fexinidazole: CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Fexinidazole. Risk X: Avoid
Finerenone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Finerenone. Risk X: Avoid
Flibanserin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Flibanserin. Risk X: Avoid
Fosamprenavir: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Fosamprenavir. Risk C: Monitor
Fosaprepitant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Fosaprepitant. Specifically, CYP3A4 Inducers (Moderate) may decrease serum concentrations of the active metabolite aprepitant. Risk C: Monitor
Fosnetupitant: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Fosnetupitant. Risk C: Monitor
Fostamatinib: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Fostamatinib. Risk C: Monitor
Fruquintinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Fruquintinib. Management: Avoid this combination when possible. If combined, continue the same fruquintinib dose, but monitor for reduced fruquintinib efficacy. Risk D: Consider Therapy Modification
Ganaxolone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ganaxolone. Management: Avoid concomitant use of ganaxolone and moderate CYP3A4 inducers whenever possible. If combined, consider increasing the dose of ganaxolone, but do not exceed the maximum recommended daily dose. Risk D: Consider Therapy Modification
Gefitinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Gefitinib. Risk C: Monitor
Gemigliptin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Gemigliptin. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Gemigliptin. Risk C: Monitor
Gepirone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Gepirone. Risk C: Monitor
Gepotidacin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Gepotidacin. Risk C: Monitor
Glasdegib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Glasdegib. Management: Avoid use of glasdegib and moderate CYP3A4 inducers whenever possible. If combined, increase glasdegib dose from 100 mg daily to 200 mg daily or from 50 mg daily to 100 mg daily. Resume previous glasdegib dose 7 days after discontinuation of the inducer. Risk D: Consider Therapy Modification
Glecaprevir and Pibrentasvir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Glecaprevir and Pibrentasvir. Risk C: Monitor
GuanFACINE: CYP3A4 Inducers (Moderate) may decrease serum concentration of GuanFACINE. Management: Increase extended-release guanfacine dose by up to double when initiating guanfacine in patients taking CYP3A4 inducers or if initiating a CYP3A4 inducer in a patient already taking extended-release guanfacine. Monitor for reduced guanfacine efficacy. Risk D: Consider Therapy Modification
Hormonal Contraceptives: CYP3A4 Inducers (Moderate) may decrease serum concentration of Hormonal Contraceptives. Management: Advise patients to use an alternative method of contraception or a back-up method during coadministration, and to continue back-up contraception for 28 days after discontinuing a moderate CYP3A4 inducer to ensure contraceptive reliability. Risk D: Consider Therapy Modification
HYDROcodone: CYP3A4 Inducers (Moderate) may decrease serum concentration of HYDROcodone. Risk C: Monitor
Hydrocortisone (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Hydrocortisone (Systemic). Risk C: Monitor
Ibrexafungerp: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ibrexafungerp. Risk X: Avoid
Ibrutinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ibrutinib. Risk C: Monitor
Idelalisib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Idelalisib. Risk C: Monitor
Ifosfamide: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Ifosfamide. CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Ifosfamide. Risk C: Monitor
Imatinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Imatinib. Risk C: Monitor
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): Antibiotics may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). Risk C: Monitor
Indinavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Indinavir. Management: Consider avoiding the combination of indinavir and moderate CYP3A4 inducers whenever possible due to the risk for decreased indinavir concentrations, reduced efficacy, and development of resistance. If combined, monitor for indinavir treatment failure. Risk D: Consider Therapy Modification
Irinotecan Products: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Irinotecan Products. Specifically, concentrations of SN-38 may be reduced. Risk C: Monitor
Isavuconazonium Sulfate: CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Isavuconazonium Sulfate. Specifically, CYP3A4 Inducers (Moderate) may decrease isavuconazole serum concentrations. Risk C: Monitor
Isradipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Isradipine. Risk C: Monitor
Istradefylline: CYP3A4 Inducers (Moderate) may decrease serum concentration of Istradefylline. Risk C: Monitor
Itraconazole: CYP3A4 Inducers (Moderate) may decrease serum concentration of Itraconazole. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Itraconazole. Risk C: Monitor
Ivabradine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ivabradine. Risk X: Avoid
Ivacaftor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ivacaftor. Risk C: Monitor
Ixabepilone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ixabepilone. Risk C: Monitor
Ixazomib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ixazomib. Risk C: Monitor
Ketamine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ketamine. Risk C: Monitor
Ketoconazole (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Ketoconazole (Systemic). Risk C: Monitor
Lactobacillus and Estriol: Antibiotics may decrease therapeutic effects of Lactobacillus and Estriol. Risk C: Monitor
Lapatinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lapatinib. Risk C: Monitor
Larotrectinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Larotrectinib. Management: Double the larotrectinib dose if used together with a moderate CYP3A4 inducer. Following discontinuation of the moderate CYP3A4 inducer, resume the previous dose of larotrectinib after a period of 3 to 5 times the inducer's half-life. Risk D: Consider Therapy Modification
Lazertinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lazertinib. Risk X: Avoid
Lefamulin (Intravenous): CYP3A4 Inducers (Moderate) may decrease serum concentration of Lefamulin (Intravenous). Management: Avoid concomitant use of lefamulin (intravenous) with moderate CYP3A4 inducers unless the benefits outweigh the risks. Risk D: Consider Therapy Modification
Lefamulin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin with moderate CYP3A4 inducers unless the benefits outweigh the risks. Risk D: Consider Therapy Modification
Lemborexant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lemborexant. Risk X: Avoid
Lenacapavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lenacapavir. Risk X: Avoid
Leniolisib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Leniolisib. Risk X: Avoid
Lercanidipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lercanidipine. Risk C: Monitor
Letermovir: Nafcillin may decrease serum concentration of Letermovir. Risk X: Avoid
Levamlodipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Levamlodipine. Risk C: Monitor
Levoketoconazole: CYP3A4 Inducers (Moderate) may decrease serum concentration of Levoketoconazole. Risk C: Monitor
Levomethadone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Levomethadone. Risk C: Monitor
LinaGLIPtin: CYP3A4 Inducers (Moderate) may decrease serum concentration of LinaGLIPtin. Risk C: Monitor
Lonafarnib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lonafarnib. Risk X: Avoid
Lopinavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lopinavir. Risk C: Monitor
Lorlatinib: CYP3A4 Inducers (Moderate) may increase hepatotoxic effects of Lorlatinib. CYP3A4 Inducers (Moderate) may decrease serum concentration of Lorlatinib. Management: Avoid use of lorlatinib with moderate CYP3A4 inducers. If such a combination must be used, increase lorlatinib to 125 mg daily. Monitor for reduced lorlatinib efficacy and consider closer monitoring of AST, ALT, and bilirubin. Risk D: Consider Therapy Modification
Lovastatin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lovastatin. Risk C: Monitor
Lumacaftor and Ivacaftor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lumacaftor and Ivacaftor. Risk C: Monitor
Lumateperone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lumateperone. Risk X: Avoid
Lurasidone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Lurasidone. Management: After chronic treatment (7 days or more) with a moderate CYP3A4 inducer, lurasidone dose increases may be needed. Monitor closely for decreased lurasidone effects and increase the lurasidone dose as needed. Risk D: Consider Therapy Modification
Macitentan: CYP3A4 Inducers (Moderate) may decrease serum concentration of Macitentan. Risk C: Monitor
Maraviroc: CYP3A4 Inducers (Moderate) may decrease serum concentration of Maraviroc. Management: Increase maraviroc adult dose to 600 mg twice/day, but only if not receiving a strong CYP3A4 inhibitor. Not recommended for pediatric patients not also receiving a strong CYP3A4 inhibitor. Contraindicated in patients with CrCl less than 30 mL/min. Risk D: Consider Therapy Modification
Maribavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Maribavir. Risk C: Monitor
Mavacamten: CYP3A4 Inducers (Moderate) may decrease serum concentration of Mavacamten. Risk X: Avoid
Mavorixafor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Mavorixafor. Risk C: Monitor
Mefloquine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Mefloquine. Risk C: Monitor
Meperidine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Meperidine. CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Meperidine. Specifically, concentrations of normeperidine, the CNS stimulating metabolite, may be increased. Risk C: Monitor
Methadone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Methadone. Risk C: Monitor
Methotrexate: Penicillins may increase serum concentration of Methotrexate. Risk C: Monitor
MethylPREDNISolone: CYP3A4 Inducers (Moderate) may decrease serum concentration of MethylPREDNISolone. Risk C: Monitor
Mianserin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Mianserin. Risk C: Monitor
Midazolam: CYP3A4 Inducers (Moderate) may decrease serum concentration of Midazolam. Risk C: Monitor
Midostaurin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Midostaurin. Risk C: Monitor
MiFEPRIStone: CYP3A4 Inducers (Moderate) may decrease serum concentration of MiFEPRIStone. Management: Avoid combined use in patients treated for Cushing's disease. When used for pregnancy termination, mifepristone efficacy may be reduced and an alternative pregnancy termination procedure may be warranted. Ensure a follow-up assessment after combined use. Risk D: Consider Therapy Modification
Mirodenafil: CYP3A4 Inducers (Moderate) may decrease serum concentration of Mirodenafil. Risk C: Monitor
Mitapivat: CYP3A4 Inducers (Moderate) may decrease serum concentration of Mitapivat. Management: Consider alternatives to this combination when possible. If combined, monitor hemoglobin and titrate mitapivat beyond 50 mg twice daily, if needed, but do not exceed doses of 100 mg twice daily. Risk D: Consider Therapy Modification
Mobocertinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Mobocertinib. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Mobocertinib. Risk X: Avoid
Montelukast: CYP3A4 Inducers (Moderate) may decrease serum concentration of Montelukast. Risk C: Monitor
Mycophenolate: Antibiotics may decrease active metabolite exposure of Mycophenolate. Specifically, concentrations of mycophenolic acid (MPA) may be reduced. Risk C: Monitor
Naldemedine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Naldemedine. Risk C: Monitor
Naloxegol: CYP3A4 Inducers (Moderate) may decrease serum concentration of Naloxegol. Risk C: Monitor
Nelfinavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Nelfinavir. Risk C: Monitor
Neratinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Neratinib. Risk X: Avoid
Netupitant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Netupitant. Risk C: Monitor
Nevirapine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Nevirapine. Risk C: Monitor
NIFEdipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of NIFEdipine. Risk C: Monitor
Nilotinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Nilotinib. Risk C: Monitor
Nilvadipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Nilvadipine. Risk C: Monitor
NiMODipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of NiMODipine. Risk C: Monitor
Nirmatrelvir and Ritonavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Nirmatrelvir and Ritonavir. Risk C: Monitor
Nirogacestat: CYP3A4 Inducers (Moderate) may decrease serum concentration of Nirogacestat. Risk X: Avoid
Nisoldipine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Nisoldipine. Risk X: Avoid
Olaparib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Olaparib. Risk X: Avoid
Oliceridine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Oliceridine. Risk C: Monitor
Olmutinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Olmutinib. Risk C: Monitor
Olutasidenib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Olutasidenib. Risk X: Avoid
Omaveloxolone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Omaveloxolone. Risk X: Avoid
Osimertinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Osimertinib. Risk C: Monitor
OxyCODONE: CYP3A4 Inducers (Moderate) may decrease serum concentration of OxyCODONE. Risk C: Monitor
PACLitaxel (Conventional): CYP3A4 Inducers (Moderate) may decrease serum concentration of PACLitaxel (Conventional). Risk C: Monitor
PACLitaxel (Protein Bound): CYP3A4 Inducers (Moderate) may decrease serum concentration of PACLitaxel (Protein Bound). Risk C: Monitor
Pacritinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Pacritinib. Risk C: Monitor
Palbociclib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Palbociclib. Risk C: Monitor
Paliperidone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Paliperidone. Risk C: Monitor
Palovarotene: CYP3A4 Inducers (Moderate) may decrease serum concentration of Palovarotene. Risk X: Avoid
PAZOPanib: CYP3A4 Inducers (Moderate) may decrease serum concentration of PAZOPanib. Risk C: Monitor
Pemigatinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Pemigatinib. Risk X: Avoid
Perampanel: CYP3A4 Inducers (Moderate) may decrease serum concentration of Perampanel. Management: Increase perampanel starting dose to 4 mg/day if used with moderate CYP3A4 inducers. Increase perampanel dose by 2 mg/day no more than once weekly based on response and tolerability. Dose adjustments may be needed if the inducer is discontinued. Risk D: Consider Therapy Modification
Pimavanserin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Pimavanserin. Risk X: Avoid
Piperaquine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Piperaquine. Risk C: Monitor
Pirtobrutinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Pirtobrutinib. Management: Avoid concomitant use if possible. If combined, if the current pirtobrutinib dose is 200 mg once daily, increase to 300 mg once daily. If current pirtobrutinib dose is 50 mg or 100 mg once daily, increase the dose by 50 mg. Risk D: Consider Therapy Modification
PONATinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of PONATinib. Risk C: Monitor
Pralsetinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Pralsetinib. Management: If this combo cannot be avoided, increase pralsetinib dose from 400 mg daily to 600 mg daily; from 300 mg daily to 500 mg daily; and from 200 mg daily to 300 mg daily. Risk D: Consider Therapy Modification
Praziquantel: CYP3A4 Inducers (Moderate) may decrease serum concentration of Praziquantel. Management: Consider alternatives to this combination whenever possible. If combined, monitor closely for reduced praziquantel efficacy. If possible, stop the moderate CYP3A4 inducer 2 to 4 weeks before praziquantel initiation. Risk D: Consider Therapy Modification
PrednisoLONE (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of PrednisoLONE (Systemic). Risk C: Monitor
PredniSONE: CYP3A4 Inducers (Moderate) may decrease serum concentration of PredniSONE. Risk C: Monitor
Pretomanid: CYP3A4 Inducers (Moderate) may decrease serum concentration of Pretomanid. Risk X: Avoid
Probenecid: May increase serum concentration of Penicillins. Risk C: Monitor
QUEtiapine: CYP3A4 Inducers (Moderate) may decrease serum concentration of QUEtiapine. Risk C: Monitor
QuiNIDine: CYP3A4 Inducers (Moderate) may decrease serum concentration of QuiNIDine. Risk C: Monitor
QuiNINE: CYP3A4 Inducers (Moderate) may decrease serum concentration of QuiNINE. Risk C: Monitor
Quizartinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Quizartinib. Risk X: Avoid
Ranolazine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ranolazine. Risk X: Avoid
Regorafenib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Regorafenib. CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Regorafenib. Risk C: Monitor
Repaglinide: CYP3A4 Inducers (Moderate) may decrease serum concentration of Repaglinide. Risk C: Monitor
Repotrectinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Repotrectinib. Risk X: Avoid
Revumenib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Revumenib. Risk X: Avoid
Ribociclib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ribociclib. Risk C: Monitor
Rilpivirine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Rilpivirine. Risk C: Monitor
Rimegepant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Rimegepant. Risk X: Avoid
Ripretinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ripretinib. Management: Avoid this combination if possible. If concomitant use is required, increase ripretinib to 150 mg twice daily. Decrease ripretinib to 150 mg once daily 14 days after stopping a moderate CYP3A4 inducer. Monitor patients for ripretinib response and toxicity Risk D: Consider Therapy Modification
RisperiDONE: CYP3A4 Inducers (Moderate) may decrease serum concentration of RisperiDONE. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of RisperiDONE. Risk C: Monitor
Ritlecitinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ritlecitinib. Risk C: Monitor
Ritonavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ritonavir. Risk C: Monitor
Roflumilast (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Roflumilast (Systemic). CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Roflumilast (Systemic). Risk C: Monitor
Rolapitant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Rolapitant. Risk C: Monitor
Samidorphan: CYP3A4 Inducers (Moderate) may decrease serum concentration of Samidorphan. Risk C: Monitor
Saquinavir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Saquinavir. Risk C: Monitor
Selpercatinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Selpercatinib. Risk X: Avoid
Selumetinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Selumetinib. Risk X: Avoid
Sertraline: CYP3A4 Inducers (Moderate) may decrease serum concentration of Sertraline. Risk C: Monitor
Sildenafil: CYP3A4 Inducers (Moderate) may decrease serum concentration of Sildenafil. Risk C: Monitor
Simeprevir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Simeprevir. Risk X: Avoid
Simvastatin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Simvastatin. Risk C: Monitor
Sirolimus (Conventional): CYP3A4 Inducers (Moderate) may decrease serum concentration of Sirolimus (Conventional). Risk C: Monitor
Sirolimus (Protein Bound): CYP3A4 Inducers (Moderate) may decrease serum concentration of Sirolimus (Protein Bound). Risk C: Monitor
Sodium Benzoate: Penicillins may decrease therapeutic effects of Sodium Benzoate. Risk C: Monitor
Sodium Picosulfate: Antibiotics may decrease therapeutic effects of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Risk D: Consider Therapy Modification
Sonidegib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Sonidegib. Risk X: Avoid
SORAfenib: CYP3A4 Inducers (Moderate) may decrease serum concentration of SORAfenib. Risk C: Monitor
Sotorasib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Sotorasib. Risk C: Monitor
Sparsentan: CYP3A4 Inducers (Moderate) may decrease serum concentration of Sparsentan. Risk C: Monitor
SUFentanil: CYP3A4 Inducers (Moderate) may decrease serum concentration of SUFentanil. Risk C: Monitor
SUNItinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of SUNItinib. Risk C: Monitor
Suvorexant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Suvorexant. Risk C: Monitor
Suzetrigine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Suzetrigine. Risk X: Avoid
Tacrolimus (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Tacrolimus (Systemic). Risk C: Monitor
Tadalafil: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tadalafil. Risk C: Monitor
Tamoxifen: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tamoxifen. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Tamoxifen. Risk C: Monitor
Tasimelteon: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tasimelteon. Risk C: Monitor
Tazemetostat: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tazemetostat. Risk X: Avoid
Temsirolimus: CYP3A4 Inducers (Moderate) may decrease serum concentration of Temsirolimus. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Temsirolimus. Specifically, sirolimus concentrations may be decreased. Risk C: Monitor
Teniposide: CYP3A4 Inducers (Moderate) may decrease serum concentration of Teniposide. Risk C: Monitor
Tetracyclines: May decrease therapeutic effects of Penicillins. Risk C: Monitor
Tetrahydrocannabinol and Cannabidiol: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tetrahydrocannabinol and Cannabidiol. Risk C: Monitor
Tetrahydrocannabinol: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tetrahydrocannabinol. Risk C: Monitor
Tezacaftor and Ivacaftor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tezacaftor and Ivacaftor. Risk C: Monitor
Thiotepa: CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Thiotepa. CYP3A4 Inducers (Moderate) may decrease serum concentration of Thiotepa. Risk C: Monitor
Ticagrelor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ticagrelor. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Ticagrelor. Risk C: Monitor
Tivozanib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tivozanib. Risk C: Monitor
Tofacitinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tofacitinib. Risk C: Monitor
Tolvaptan: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tolvaptan. Risk C: Monitor
Toremifene: CYP3A4 Inducers (Moderate) may decrease serum concentration of Toremifene. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Toremifene. Risk C: Monitor
Trabectedin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Trabectedin. Risk C: Monitor
TraMADol: CYP3A4 Inducers (Moderate) may decrease serum concentration of TraMADol. Risk C: Monitor
TraZODone: CYP3A4 Inducers (Moderate) may decrease serum concentration of TraZODone. Risk C: Monitor
Tretinoin (Systemic): CYP3A4 Inducers (Moderate) may decrease serum concentration of Tretinoin (Systemic). Risk C: Monitor
Triazolam: CYP3A4 Inducers (Moderate) may decrease serum concentration of Triazolam. Risk C: Monitor
Tucatinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Tucatinib. Risk C: Monitor
Typhoid Vaccine: Antibiotics may decrease therapeutic effects of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Avoid use of live attenuated typhoid vaccine (Ty21a) in patients being treated with systemic antibacterial agents. Postpone vaccination until 3 days after cessation of antibiotics and avoid starting antibiotics within 3 days of last vaccine dose. Risk D: Consider Therapy Modification
Ubrogepant: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ubrogepant. Management: Use an initial ubrogepant dose of 100 mg and second dose (if needed) of 100 mg when used with a moderate CYP3A4 inducer. Risk D: Consider Therapy Modification
Ulipristal: CYP3A4 Inducers (Moderate) may decrease serum concentration of Ulipristal. Risk X: Avoid
Upadacitinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Upadacitinib. Risk C: Monitor
Valbenazine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Valbenazine. CYP3A4 Inducers (Moderate) may decrease active metabolite exposure of Valbenazine. Risk C: Monitor
Vandetanib: CYP3A4 Inducers (Moderate) may increase active metabolite exposure of Vandetanib. CYP3A4 Inducers (Moderate) may decrease serum concentration of Vandetanib. Risk C: Monitor
Vanzacaftor, Tezacaftor, and Deutivacaftor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Vanzacaftor, Tezacaftor, and Deutivacaftor. Risk X: Avoid
Velpatasvir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Velpatasvir. Risk X: Avoid
Vemurafenib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Vemurafenib. Risk C: Monitor
Venetoclax: CYP3A4 Inducers (Moderate) may decrease serum concentration of Venetoclax. Risk X: Avoid
Verapamil: CYP3A4 Inducers (Moderate) may decrease serum concentration of Verapamil. Risk C: Monitor
Vilazodone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Vilazodone. Risk C: Monitor
VinCRIStine: CYP3A4 Inducers (Moderate) may decrease serum concentration of VinCRIStine. Risk C: Monitor
Vitamin K Antagonists: Nafcillin may decrease anticoagulant effects of Vitamin K Antagonists. Management: Consider choosing an alternative antibiotic. Monitor for decreased therapeutic effects and need for dose adjustments of vitamin K antagonists if nafcillin is initiated/dose increased, or increased effects if nafcillin is discontinued/dose decreased. Risk D: Consider Therapy Modification
Voclosporin: CYP3A4 Inducers (Moderate) may decrease serum concentration of Voclosporin. Risk X: Avoid
Vonoprazan: CYP3A4 Inducers (Moderate) may decrease serum concentration of Vonoprazan. Risk X: Avoid
Vorapaxar: CYP3A4 Inducers (Moderate) may decrease serum concentration of Vorapaxar. Risk X: Avoid
Voriconazole: CYP3A4 Inducers (Moderate) may decrease serum concentration of Voriconazole. Risk C: Monitor
Vortioxetine: CYP3A4 Inducers (Moderate) may decrease serum concentration of Vortioxetine. Risk C: Monitor
Voxelotor: CYP3A4 Inducers (Moderate) may decrease serum concentration of Voxelotor. Management: Avoid concomitant use of voxelotor and moderate CYP3A4 inducers. If unavoidable, increase the voxelotor dose to 2,000 mg once daily. For children ages 4 to less than 12 years, weight-based dose adjustments are required. See full monograph for details. Risk D: Consider Therapy Modification
Voxilaprevir: CYP3A4 Inducers (Moderate) may decrease serum concentration of Voxilaprevir. Risk X: Avoid
Zaleplon: CYP3A4 Inducers (Moderate) may decrease serum concentration of Zaleplon. Risk C: Monitor
Zanubrutinib: CYP3A4 Inducers (Moderate) may decrease serum concentration of Zanubrutinib. Management: Avoid this combination if possible. If coadministration of zanubrutinib and a moderate CYP3A4 inducer is required, increase the zanubrutinib dose to 320 mg twice daily. Risk D: Consider Therapy Modification
Zolpidem: CYP3A4 Inducers (Moderate) may decrease serum concentration of Zolpidem. Risk C: Monitor
Zopiclone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Zopiclone. Risk C: Monitor
Zuranolone: CYP3A4 Inducers (Moderate) may decrease serum concentration of Zuranolone. Risk X: Avoid
Penicillin class antibiotics cross the placenta in varying degrees. Nafcillin is highly protein bound which may limit fetal exposure (Nau 1987).
As a class, penicillin antibiotics are widely used in pregnant women. Based on available data, penicillin antibiotics are generally considered compatible for use during pregnancy (Ailes 2016; Bookstaver 2015; Crider 2009; Damkier 2019; Lamont 2014; Muanda 2017a; Muanda 2017b).
Penicillins are present in breast milk.
Concentrations of penicillin class antibiotics in breast milk are limited (Nau 1987). The manufacturer recommends that caution be exercised when administering nafcillin to breastfeeding women. In general, antibiotics that are present in breast milk may cause non-dose-related modification of bowel flora. Monitor infants for GI disturbances, such as thrush or diarrhea (WHO 2002).
Some products may contain sodium.
Baseline and periodic CBC with differential, urinalysis, BUN, serum creatinine; baseline and periodic serum bilirubin, AST, ALT, serum potassium (especially with high doses or prolonged therapy), alkaline phosphatase and gamma glutamyl transferase (especially when using high doses); observe for signs and symptoms of anaphylaxis during first dose. Monitor infusion site.
Interferes with bacterial cell wall synthesis during active multiplication, causing cell wall destruction and resultant bactericidal activity against susceptible bacteria; resistant to inactivation by staphylococcal penicillinase
Distribution: Widely distributed; CSF penetration is poor but enhanced by meningeal inflammation.
Vd:
Preterm neonates (GA 28 to 33 weeks; PNA 5 to 68 days): 0.242 to 0.534 L/kg (Banner 1980).
Infants, Children, and Adolescents ≤13 years of age: 0.893 ± 0.083 L/kg (Feldman 1978).
Adults: 0.57 to 1.55 L/kg.
Protein binding: ~90%; primarily to albumin.
Metabolism: Primarily hepatic; undergoes enterohepatic recirculation.
Half-life elimination:
Preterm neonates (GA 28 to 33 weeks) (Banner 1980):
PNA <3 weeks: 2.23 to 5.46 hours.
PNA ≥3 to 9 weeks: 1.24 to 2.26 hours.
Infants, Children, and Adolescents ≤13 years of age : 0.76 ± 0.03 hours (Feldman 1978).
Adults: Normal renal/hepatic function: 33 to 61 minutes.
Time to peak, serum: IM: 30 to 60 minutes.
Excretion: Primarily feces; urine (~30% as unchanged drug).
Hepatic function impairment: Plasma clearance is significantly decreased and excretion in urine was significantly increased from ~30% to 50% in patients with biliary obstruction and cirrhosis.
Anti-infective considerations:
Parameters associated with efficacy: Time dependent, associated with time free drug concentration (fT) > minimum inhibitory concentration (MIC); goal: ≥50% fT > MIC (bactericidal) (Drusano 2003; Turnidge 1998).
Critically ill patients in the ICU: Minimum goal: ≥50% fT > MIC; preferred goal: ≥100% fT > MIC (Abdul-Aziz 2020; Al-Shaer 2020; Roberts 2014); some experts favor ≥100% fT > 4 times the MIC (Guilhaumou 2019).
Expected drug exposure in normal renal function:
Cmax (peak): Single dose: IV:
Infants, children, and adolescents ≤13 years of age: 37.5 mg/kg (infused over 15 minutes): 48.1 ± 3.5 mg/L (Feldman 1978).
Adults: 500 mg (infused over 7 minutes): ~30 mg/L.
Postantibiotic effect: Minimal bacterial killing continues after concentration of penicillins fall below the MIC of targeted pathogen and varies based on the organism:
Gram-positive cocci: 1.5 to 3.5 hours (Craig 1991).
Gram-negative bacilli: 0 to 1.5 hours (Craig 1991).
Parameters associated with toxicity: Continuous infusion: Hospitalized adults: In a retrospective study, steady-state nafcillin concentrations were significantly higher in patients who experienced an adverse drug event compared to those who did not (66 vs 25.5 mg/L). Specifically, concentrations were higher in patients who experienced hepatotoxicity (62.8 vs 27 mg/L), nausea/vomiting (80 vs 28.5 mg/L), and diarrhea (66.5 vs 26.5 mg/L) (Benefield 2016).
