Dosage Forms
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)
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); 10 g (1 ea)
Solution Reconstituted, Intravenous:
Generic: 2 g (1 ea [DSC])
Solution Reconstituted, Intravenous [preservative free]:
Generic: 1 g (1 ea); 2 g (1 ea); 10 g (1 ea)
Pharmacology
Mechanism of Action
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
Pharmacokinetics/Pharmacodynamics
Distribution
Widely distributed; CSF penetration is poor but enhanced by meningeal inflammation
Vd: Neonates: 0.24 to 0.53 L/kg; Children: 0.85 to 0.91 L/kg; Adults: 0.57 to 1.55 L/kg
Metabolism
Primarily hepatic; undergoes enterohepatic recirculation
Excretion
Primarily feces; urine (~30% as unchanged drug)
Time to Peak
Serum: IM: 30-60 minutes
Half-Life Elimination
Neonates <3 weeks: 2.2 to 5.5 hours; 4 to 9 weeks: 1.2 to 2.3 hours
Infants and Children 1 month to 14 years: 0.75 to 1.9 hours
Adults: Normal renal/hepatic function: 33 to 61 minutes
Protein Binding
~90%; primarily to albumin
Use in Specific Populations
Special Populations: Hepatic Function Impairment
Plasma clearance is significantly decreased and excretion in urine was significantly increased from approximately 30% to 50% in patients with biliary obstruction and cirrhosis.
Use: Labeled Indications
Staphylococcal infections: Treatment of infections caused by susceptible penicillinase-producing staphylococci
Use: Off Label
Catheter-related bloodstream infectionsyes
Based on the Infectious Diseases Society of America (IDSA) clinical practice guidelines for the diagnosis and management of intravascular catheter-related infections, nafcillin is effective and recommended for the treatment of catheter-related bloodstream infections caused by methicillin-susceptible S. aureus or methicillin-susceptible coagulase-negative Staphylococcus species.
Skin and soft tissue necrotizing infectionyes
Based on the IDSA guidelines for the diagnosis and management of skin and soft tissue infections (SSTI), nafcillin is an effective and recommended option for treatment of necrotizing infections of the skin, fascia, and muscle due to methicillin-sensitive Staphylococcus aureus.
Streptococcal skin infectionsyes
Based on the IDSA guidelines for the diagnosis and management of skin and soft tissue infections (SSTI), nafcillin is an effective and recommended option for treatment of streptococcal skin infections.
Surgical site infectionsyes
Based on the IDSA guidelines for the diagnosis and management of SSTIs, nafcillin is an effective and recommended option for treatment of surgical site infections occurring after surgery of the trunk or extremity (away from the axilla or perineum). Systemic antibacterials are not routinely indicated for surgical site infections, but may be beneficial (in conjunction with suture removal plus incision and drainage) in patients with significant systemic response (eg, temperature >38.5ºC, heart rate >110 beats per minute, erythema/induration extending >5 cm from incision, WBC >12,000/mm3).
Contraindications
Hypersensitivity to nafcillin, other penicillins, or any component of the formulation.
Documentation of allergenic cross-reactivity for beta-lactams (eg, penicillins and cephalosporins) is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.
Dosage and Administration
Dosing: Adult
Catheter-related bloodstream infections (off-label use): IV: 2 g every 4 hours (IDSA [Mermel 2009])
Endocarditis: Methicillin-susceptible Staphylococcus aureus (MSSA) (off-label dose): IV:
Native valve: 12 g/day in 4 or 6 divided doses (ie, 2 g every 4 hours or 3 g every 6 hours) for 6 weeks. Note: Duration intended for complicated right-sided infective endocarditis (IE) or left-sided IE. For uncomplicated right-sided IE, 2 weeks of therapy may be adequate (AHA [Baddour 2015]).
Prosthetic valve: 12 g/day in 6 divided doses (ie, 2 g every 4 hours) for ≥6 weeks (use with rifampin for entire course and gentamicin for first 2 weeks) (AHA [Baddour 2015])
Meningitis, bacterial: Methicillin-susceptible S. aureus (off-label dose): IV: 2 g every 4 hours; consider addition of rifampin if organism is susceptible and prosthetic material is present (IDSA [Tunkel 2004]; IDSA [Tunkel 2017])
Osteomyelitis: Methicillin-susceptible S. aureus (MSSA) (off-label dose): IV: 1.5 to 2 g every 4 to 6 hours or via continuous infusion (IDSA [Berbari 2015])
Prosthetic joint infections: Methicillin-susceptible S. aureus (MSSA) (off-label dose): 1.5 to 2 g every 4 to 6 hours (IDSA [Osmon 2013])
Skin and soft tissue infections (IDSA [Stevens 2014]):
Due to methicillin-susceptible Staphylococcus aureus (MSSA) (off-label dose): IV: 1 to 2 g every 4 hours for 7 to 14 days
Necrotizing infection due to MSSA (off-label use): 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
Streptococcal skin infections (off-label use): IV: 1 to 2 g every 4 to 6 hours (IDSA [Stevens 2014])
Surgical site infections (trunk or extremity [away from axilla or perineum]) (off-label use): IV: 2 g every 6 hours (IDSA [Stevens 2014])
Dosing: Geriatric
Refer to adult dosing.
Dosing: Pediatric
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; for severe infections, doses at the higher end of the range should be considered (Bradley 2019; Red Book [AAP 2018]).
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 (Knoderer 2017).
Endocarditis, treatment (AHA [Baltimore 2015]): 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 (AHA [Baltimore 2015]).
Meningitis, including healthcare associated ventriculitis/meningitis; MSSA: 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 (IDSA [Tunkel 2004]; IDSA [Tunkel 2017]).
Skin and soft tissue infections (IDSA [Stevens 2014]): Infants, Children, and Adolescents:
MSSA: 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.
Necrotizing infection due to MSSA: 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.
Reconstitution
Parenteral:
IM: Reconstitute with NS, SWFI or bacteriostatic water for injection; resultant concentration is 250 mg/mL
IV: Reconstitute powder for injection with NS, or SWFI, resultant concentration dependent upon product (see manufacturer's labeling for specific details)
Direct IV injection: Further dilute dose in 15 to 30 mL of NS or SWFI
Intermittent IV infusion: Further dilute in an appropriate fluid, final concentration should not exceed 40 mg/mL (Klaus 1989); in fluid-restricted patients, a higher concentration may be used depending on the diluent (D5W: 71 mg/mL; NS: 62 mg/mL; SWI: 125 mg/mL) (Robinson 1987)
Administration
IM: Administer as a deep intragluteal injection; rotate injection sites.
IV: Infuse over 30 to 60 minutes. Vesicant; ensure proper needle or catheter placement prior to and during IV infusion. Avoid extravasation.
Extravasation management: If extravasation occurs, stop infusion immediately and disconnect (leave needle/cannula in place); gently aspirate extravasated solution (do NOT flush the line); initiate hyaluronidase antidote; remove needle/cannula (if not using IV hyaluronidase antidote), apply dry cold compresses (Hurst 2004, Reynolds 2014); elevate extremity.
Hyaluronidase: Intradermal or SubQ: Inject a total of 1 to 1.7 mL (15 units/mL) as 5 separate 0.2 to 0.3 mL injections (using a 25-gauge needle) into area of extravasation at the leading edge in a clockwise manner (MacCara 1983, Reynolds 2014, Zenk 1981).
Dietary Considerations
Some products may contain sodium.
Storage
Premixed infusions: Store in a freezer at -20°C (-4°F). Thaw at room temperature or under refrigeration only. Thawed bags are stable for 21 days under refrigeration or 72 hours at room temperature. Do not refreeze.
Vials: Store at 20°C to 25°C (68°F to 77°F). Reconstituted parenteral solution is stable for 3 days at room temperature and 7 days when refrigerated. For IV infusion in NS or D5W, solution is stable for 24 hours at room temperature and 7 days when refrigerated.
Solutions for ambulatory IV infusion reservoirs (eg, >24-hour supply) may be subject to inadvertent exposure to temperatures higher than recommended due to heat radiation from patient's skin; lower concentrations of preparation may be needed to prevent precipitation of solution in some circumstances (Chan 2005).
Drug Interactions
Abemaciclib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Abemaciclib. Avoid combination
Acemetacin: May increase the serum concentration of Penicillins. Monitor therapy
Antihepaciviral Combination Products: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Antihepaciviral Combination Products. Avoid combination
Asunaprevir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Asunaprevir. Avoid combination
Avapritinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Avapritinib. Avoid combination
Axitinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Axitinib. Avoid combination
BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination
BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy
Bedaquiline: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Bedaquiline. Avoid combination
Benzhydrocodone: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Benzhydrocodone. Specifically, the serum concentrations of hydrocodone may be reduced. Monitor therapy
Bosutinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Bosutinib. Avoid combination
Brigatinib: CYP3A4 Inducers (Moderate) may decrease the 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. Consider therapy modification
Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Avoid combination
Clarithromycin: CYP3A4 Inducers (Moderate) may increase serum concentrations of the active metabolite(s) of Clarithromycin. CYP3A4 Inducers (Moderate) may decrease the serum concentration of Clarithromycin. Management: Consider alternative antimicrobial therapy for patients receiving a CYP3A inducer. Drugs that enhance the metabolism of clarithromycin into 14-hydroxyclarithromycin may alter the clinical activity of clarithromycin and impair its efficacy. Consider therapy modification
CloZAPine: CYP3A4 Inducers (Moderate) may decrease the serum concentration of CloZAPine. Monitor therapy
Cobimetinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Cobimetinib. Avoid combination
Codeine: CYP3A4 Inducers (Moderate) may decrease serum concentrations of the active metabolite(s) of Codeine. Monitor therapy
CycloSPORINE (Systemic): Nafcillin may increase the metabolism of CycloSPORINE (Systemic). Monitor therapy
CYP3A4 Substrates (High risk with Inducers): CYP3A4 Inducers (Moderate) may decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Exceptions: Apixaban; Rivaroxaban. Monitor therapy
Daclatasvir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Daclatasvir. Management: Increase the daclatasvir dose to 90 mg once daily if used with a moderate CYP3A4 inducer. Consider therapy modification
Dasabuvir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Dasabuvir. Avoid combination
Deflazacort: CYP3A4 Inducers (Moderate) may decrease serum concentrations of the active metabolite(s) of Deflazacort. Avoid combination
Dichlorphenamide: Penicillins may enhance the hypokalemic effect of Dichlorphenamide. Monitor therapy
Doravirine: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Doravirine. Monitor therapy
Elbasvir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Elbasvir. Avoid combination
Elexacaftor, Tezacaftor, and Ivacaftor: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Elexacaftor, Tezacaftor, and Ivacaftor. Monitor therapy
Encorafenib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Encorafenib. Avoid combination
Entrectinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Entrectinib. Avoid combination
Erdafitinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Erdafitinib. Management: Dose modifications of erdafitinib may be required. See full monograph for details. Consider therapy modification
Estriol (Systemic): CYP3A4 Inducers (Moderate) may decrease the serum concentration of Estriol (Systemic). Monitor therapy
Estriol (Topical): CYP3A4 Inducers (Moderate) may decrease the serum concentration of Estriol (Topical). Monitor therapy
Estrogen Derivatives (Contraceptive): Nafcillin may increase the metabolism of Estrogen Derivatives (Contraceptive). Management: Use of an alternative, nonhormonal form of contraception during nafcillin therapy is recommended. Consider therapy modification
Fedratinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Fedratinib. Avoid combination
FentaNYL: CYP3A4 Inducers (Moderate) may decrease the serum concentration of FentaNYL. Monitor therapy
Flibanserin: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Flibanserin. Avoid combination
Glecaprevir and Pibrentasvir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Glecaprevir and Pibrentasvir. Monitor therapy
Grazoprevir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Grazoprevir. Avoid combination
GuanFACINE: CYP3A4 Inducers (Moderate) may decrease the serum concentration of GuanFACINE. Management: Increase the guanfacine dose by up to double when initiating guanfacine in a patient taking a moderate CYP3A4 inducer. Increase guanfacine dose gradually over 1 to 2 weeks if initiating a moderate CYP3A4 inducer in a patient already taking guanfacine. Consider therapy modification
HYDROcodone: CYP3A4 Inducers (Moderate) may decrease the serum concentration of HYDROcodone. Monitor therapy
Ibrutinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Ibrutinib. Monitor therapy
Ifosfamide: CYP3A4 Inducers (Moderate) may decrease serum concentrations of the active metabolite(s) of Ifosfamide. CYP3A4 Inducers (Moderate) may increase serum concentrations of the active metabolite(s) of Ifosfamide. Monitor therapy
Istradefylline: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Istradefylline. Monitor therapy
Ivacaftor: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Ivacaftor. Monitor therapy
Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy
Lefamulin: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin with moderate CYP3A4 inducers unless the benefits outweigh the risks. Consider therapy modification
Lefamulin (Intravenous): CYP3A4 Inducers (Moderate) may decrease the serum concentration of Lefamulin (Intravenous). Management: Avoid concomitant use of lefamulin (intravenous) with moderate CYP3A4 inducers unless the benefits outweigh the risks. Consider therapy modification
Lemborexant: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Lemborexant. Avoid combination
Letermovir: Nafcillin may decrease the serum concentration of Letermovir. Avoid combination
Lorlatinib: CYP3A4 Inducers (Moderate) may enhance the hepatotoxic effect of Lorlatinib. CYP3A4 Inducers (Moderate) may decrease the serum concentration of Lorlatinib. Management: Avoid use of lorlatinib with moderate CYP3A4 inducers. If such a combination must be used, monitor AST, ALT, and bilirubin within 48 hours of starting the combination and at least three times within the first week of combined use. Consider therapy modification
Lumacaftor and Ivacaftor: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Lumacaftor and Ivacaftor. Monitor therapy
Lumateperone: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Lumateperone. Avoid combination
Lurasidone: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Lurasidone. Management: Monitor for decreased lurasidone effects if combined with moderate CYP3A4 inducers and consider increasing the lurasidone dose if coadministered with a moderate CYP3A4 inducer for 7 or more days. Consider therapy modification
Meperidine: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Meperidine. Monitor therapy
Methotrexate: Penicillins may increase the serum concentration of Methotrexate. Monitor therapy
Mirodenafil: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Mirodenafil. Monitor therapy
Mycophenolate: Penicillins may decrease serum concentrations of the active metabolite(s) of Mycophenolate. This effect appears to be the result of impaired enterohepatic recirculation. Monitor therapy
Naldemedine: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Naldemedine. Monitor therapy
Neratinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Neratinib. Avoid combination
NIFEdipine: Nafcillin may decrease the serum concentration of NIFEdipine. Consider therapy modification
NiMODipine: CYP3A4 Inducers (Moderate) may decrease the serum concentration of NiMODipine. Monitor therapy
Nisoldipine: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Nisoldipine. Avoid combination
Olaparib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Olaparib. Avoid combination
Palbociclib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Palbociclib. Management: The US label does not provide specific recommendations concerning use with moderate CYP3A4 inducers, but the Canadian label recommends avoiding use of moderate CYP3A4 inducers. Consider therapy modification
Perampanel: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Perampanel. Management: Increase the perampanel starting dose to 4 mg/day when perampanel is used concurrently with moderate and strong CYP3A4 inducers. Consider therapy modification
Pexidartinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pexidartinib. Monitor therapy
Pimavanserin: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pimavanserin. Avoid combination
Pitolisant: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pitolisant. Monitor therapy
Pretomanid: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Pretomanid. Avoid combination
Probenecid: May increase the serum concentration of Penicillins. Monitor therapy
Ranolazine: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Ranolazine. Avoid combination
Rolapitant: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Rolapitant. Monitor therapy
Simeprevir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Simeprevir. Avoid combination
Sodium Picosulfate: Antibiotics may diminish the therapeutic effect 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. Consider therapy modification
Sonidegib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Sonidegib. Avoid combination
Tazemetostat: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Tazemetostat. Avoid combination
Tetracyclines: May diminish the therapeutic effect of Penicillins. Monitor therapy
Tezacaftor and Ivacaftor: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Tezacaftor and Ivacaftor. Monitor therapy
Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification
Ubrogepant: CYP3A4 Inducers (Moderate) may decrease the 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. Consider therapy modification
Upadacitinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Upadacitinib. Monitor therapy
Velpatasvir: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Velpatasvir. Avoid combination
Venetoclax: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Venetoclax. Avoid combination
Vitamin K Antagonists (eg, warfarin): Nafcillin may diminish the anticoagulant effect of Vitamin K Antagonists. Management: Consider choosing an alternative antibiotic. Monitor for decreased therapeutic effects and need for dose adjustments of oral anticoagulants if nafcillin is initiated/dose increased, or increased effects if nafcillin is discontinued/dose decreased. Consider therapy modification
Voxelotor: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Voxelotor. Management: Avoid concomitant use of voxelotor and moderate CYP3A4 inducers. If concomitant use is unavoidable, increase the voxelotor dose to 2,500 mg once daily. Consider therapy modification
Zanubrutinib: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Zanubrutinib. Avoid combination
Zolpidem: CYP3A4 Inducers (Moderate) may decrease the serum concentration of Zolpidem. Monitor therapy
Test Interactions
Positive Coombs' test (direct), false-positive urinary and serum proteins; may inactivate aminoglycosides in vitro
Adverse Reactions
Frequency not defined.
Cardiovascular: Local thrombophlebitis
Central nervous system: Neurotoxicity (high doses)
Gastrointestinal: Cholestasis, Clostridioides (formerly Clostridium) difficile-associated diarrhea
Hematologic & oncologic: Agranulocytosis, bone marrow depression, neutropenia
Hepatic: Increased serum transaminases
Hypersensitivity: Anaphylaxis
Local: Inflammation at injection site, injection site phlebitis, local skin exfoliation (at injection site), pain at injection site, swelling at injection site
Renal: Interstitial nephritis, renal tubular disease
<1%, postmarketing, and/or case reports: Cholestatic hepatitis
Warnings/Precautions
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). Consider serum potassium monitoring with high doses or prolonged therapy.
- 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.
Concurrent drug therapy issues:
- Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Monitoring Parameters
Baseline and periodic CBC with differential, urinalysis, BUN, serum creatinine; baseline and periodic serum bilirubin, AST, ALT, alkaline phosphatase and gamma glutamyl transferase (especially when using high doses); observe for signs and symptoms of anaphylaxis during first dose. Monitor infusion site.
Pregnancy
Pregnancy Risk Factor
B
Pregnancy Considerations
Adverse events have not been observed in animal reproduction studies. Information specific to nafcillin use in pregnancy is limited. Maternal use of penicillins has generally not resulted in an increased risk of birth defects.
Patient Education
What is this drug used for?
- It is used to treat bacterial infections.
Frequently reported side effects of this drug
- Nausea
- Vomiting
- Diarrhea
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
- Kidney problems like unable to pass urine, blood in the urine, change in amount of urine passed, or weight gain.
- Liver problems like dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin.
- Muscle weakness
- Muscle pain
- Joint pain
- Abdominal pain
- Infection
- Bruising
- Bleeding
- Severe dizziness
- Passing out
- Severe loss of strength and energy
- Twitching
- Seizure
- Burning or numbness feeling
- Severe injection site pain, redness, burning, edema, or irritation
- Clostridioides (formerly Clostridium) difficile-associated diarrhea like stomach pain or cramps, very loose or watery stools, or bloody stools.
- Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.
Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
