Nafcillin Dosage

Medically reviewed by Drugs.com. Last updated on Feb 10, 2025.

Usual Adult Dose for Bacterial Infection

IM: 500 mg IM every 4 to 6 hours
IV: 500 mg IV every 4 hours

Severe infections: 1 g IM or IV every 4 hours

Use: For the treatment of infections due to susceptible penicillinase-producing staphylococci which have shown susceptibility to this drug

Usual Adult Dose for Endocarditis

American Heart Association (AHA) Recommendations:

• Native valve infective endocarditis (NVE): 2 g IV every 4 hours or 3 g IV every 6 hours
• Prosthetic valve endocarditis: 2 g IV every 4 hours

Total dose: 12 g/day

Duration of Therapy:

• For complicated right-sided NVE and for left-sided NVE: 6 weeks
• For uncomplicated right-sided NVE: 2 weeks
• For prosthetic valve endocarditis: At least 6 weeks

Comments:

• Recommended for NVE due to oxacillin-susceptible strains of staphylococci
• With other agents, recommended for endocarditis involving prosthetic valve (or other prosthetic material) due to oxacillin-susceptible strains of staphylococci
• Current guidelines should be consulted for additional information.

Usual Adult Dose for Joint Infection

Infectious Diseases Society of America (IDSA) Recommendations: 1.5 to 2 g IV every 4 to 6 hours

Comments:

• Recommended as a preferred regimen to treat prosthetic joint infection due to oxacillin-susceptible staphylococci
• Current guidelines should be consulted for additional information.

Usual Adult Dose for Meningitis

IDSA Recommendations: 9 to 12 g/day IV divided every 4 hours

Comments:

• Recommended as a standard regimen for bacterial meningitis due to methicillin-susceptible Staphylococcus aureus (MSSA)
• Current guidelines should be consulted for additional information.

Usual Adult Dose for Osteomyelitis

IDSA Recommendations: 1.5 to 2 g IV every 4 to 6 hours
Duration of therapy: 6 weeks

Comments:

• Recommended as a preferred regimen for native vertebral osteomyelitis due to oxacillin-susceptible staphylococci
• Alternatively, the total daily dose may be administered via continuous infusion.
• Current guidelines should be consulted for additional information.

Usual Adult Dose for Skin or Soft Tissue Infection

IDSA Recommendations:

• Incisional surgical site infections: 2 g IV every 6 hours
• MSSA skin and soft tissue infection, necrotizing infections: 1 to 2 g IV every 4 hours
• Streptococcal skin infections: 1 to 2 g IV every 4 to 6 hours

Comments:

• Recommended for treatment of incisional surgical site infections associated with surgery of trunk or extremity away from axilla or perineum
• Recommended as a preferred regimen for skin and soft tissue infection due to MSSA and necrotizing infections of the skin, fascia, and muscle due to S aureus
• Recommended as a regimen for streptococcal skin infection
• Current guidelines should be consulted for additional information.

Usual Pediatric Dose for Bacterial Infection

Neonates: 10 mg/kg IM twice a day

Infants and children weighing less than 40 kg: 25 mg/kg IM twice a day

Children weighing at least 40 kg: 500 mg IM every 4 to 6 hours

• Severe infections: 1 g IM every 4 hours

Use: For the treatment of infections due to susceptible penicillinase-producing staphylococci which have shown susceptibility to this drug

American Academy of Pediatrics Recommendations:
Gestational age up to 34 weeks:

• Postnatal age up to 7 days: 25 mg/kg IV or IM every 12 hours
• Postnatal age greater than 7 days: 25 mg/kg IV or IM every 8 hours

Gestational age greater than 34 weeks:

• Postnatal age up to 7 days: 25 mg/kg IV or IM every 8 hours
• Postnatal age greater than 7 days: 25 mg/kg IV or IM every 6 hours

1 month or older: 100 to 200 mg/kg/day IV or IM divided in 4 to 6 doses
Maximum dose: 12 g/day

Comments:

• Neonates: Higher doses may be needed for meningitis, though safety and efficacy data for dosing neonates with CNS infection are lacking.
• Patient 1 month or older: The high end of the dosage should be used for meningitis.
• Current guidelines should be consulted for additional information.

Usual Pediatric Dose for Endocarditis

AHA Recommendations:
1 year or older: 200 mg/kg/day IV divided every 4 to 6 hours
Maximum dose: 12 g/day
Duration of therapy: At least 4 to 6 weeks

Comments:

• Recommended as an alternative regimen for infective endocarditis due to staphylococci (S aureus or coagulase-negative staphylococci) susceptible to 1 mcg/mL or less penicillin G
• With or without gentamicin, recommended as a preferred regimen for infective endocarditis due to staphylococci (S aureus or coagulase-negative staphylococci) resistant to 0.1 mcg/mL penicillin G
• Current guidelines should be consulted for additional information.

Usual Pediatric Dose for Meningitis

IDSA Recommendations:

• Neonates 0 to 7 days: 75 mg/kg/day IV divided every 8 to 12 hours
• Neonates 8 to 28 days: 100 to 150 mg/kg/day IV divided every 6 to 8 hours
• Infants and children: 200 mg/kg/day IV divided every 6 hours

Maximum dose: 12 g/day

Comments:

• Recommended as a standard regimen for bacterial meningitis due to MSSA
• Smaller doses and longer administration intervals may be advisable for very low birth weight neonates (less than 2 kg).
• Current guidelines should be consulted for additional information.

Usual Pediatric Dose for Pneumonia

Pediatric Infectious Diseases Society and IDSA Recommendations:

• Infants and children older than 3 months: 150 to 200 mg/kg/day IV or IM divided every 6 to 8 hours

Maximum dose: 12 g/day

Comments:

• Recommended as a preferred regimen for community-acquired pneumonia due to MSSA
• Current guidelines should be consulted for additional information.

Usual Pediatric Dose for Skin or Soft Tissue Infection

IDSA Recommendations:
1 month or older:

• Necrotizing infections, streptococcal skin infections: 50 mg/kg IV every 6 hours
• MSSA Skin and soft tissue infection: 100 to 150 mg/kg/day IV in 4 divided doses

Comments:

• Recommended as a preferred regimen for necrotizing infections of the skin, fascia, and muscle due to S aureus
• Recommended as a regimen for streptococcal skin infection
• Recommended as a preferred regimen for skin and soft tissue infection due to MSSA
• Current guidelines should be consulted for additional information.

Renal Dose Adjustments

No adjustment recommended.

Renal dysfunction with liver dysfunction: Caution recommended.

Liver Dose Adjustments

Data not available

Liver dysfunction with renal dysfunction: Caution recommended.

Comments:

• The benefit versus risk of continued therapy should be reevaluated in patients with worsening liver function.

Precautions

CONTRAINDICATIONS:

• History of hypersensitivity (anaphylactic) reaction to any penicillin
• Dextrose-containing solutions: Known allergy to corn or corn products

IV route: Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

Dialysis

Hemodialysis: No adjustment recommended.

Other Comments

Administration advice:

• May administer IM (by deep intragluteal injection), by direct IV injection (over 5 to 10 minutes), or by IV infusion (slowly over at least 30 to 60 minutes [to reduce risk of vein irritation and extravasation])
• Do not use plastic container in series connections.
• If another agent is used concomitantly, do not physically mix with this drug; administer separately.
• Determine duration of therapy by clinical and bacteriological response of patient.
• Continue therapy for at least 14 days in severe staphylococcal infections.

Storage requirements:

• Galaxy containers: Store at or below -20C (-4F); thawed solution is stable for 21 days under refrigeration (5C [41F]) or 72 hours at room temperature (25C [77F]); do not refreeze.
• Vials: Store at 20C to 25C (68F to 77F) before reconstitution; the manufacturer product information should be consulted regarding stability periods of reconstituted and/or further diluted solutions at room temperature (25C), under refrigeration (4C), or frozen (-15C).

Reconstitution/preparation techniques:

• Galaxy containers: Thaw frozen container at room temperature (25C [77F]) or in refrigerator (5C [41F]); do not force thaw by immersion in water baths or by microwave irradiation.
• Vials: The manufacturer product information should be consulted.

IV compatibility:

• Compatible reconstitution diluents for vials: Sterile Water for Injection, USP; Sodium Chloride Injection, USP
• Compatible IV solutions for vials: Sterile Water for Injection, USP; 0.9% Sodium Chloride Injection, USP; M/6 Molar Sodium Lactate Solution, USP; 5% Dextrose Injection, USP; 5% Dextrose and 0.45% Sodium Chloride Injection, USP; 10% Invert Sugar Injection, USP; Lactated Ringers Solution, USP
• Do not add supplementary medication.

General:

• Bacteriologic studies recommended to determine causative organisms and susceptibility.
• This drug should not be used in infections due to penicillin G-susceptible organisms.
• This drug should be discontinued if susceptibility tests indicate the infection is due to methicillin-resistant Staphylococcus species; alternative therapy should be provided.
• Duration of therapy varies with type and severity of infection and overall patient condition; endocarditis and osteomyelitis may require a longer duration of therapy.
• Caution recommended with IV administration (especially in elderly patients) due to possibility of thrombophlebitis; according to some manufacturers, the IV infusion route should be used for relatively short-term therapy (24 to 48 hours).

Monitoring:

• General: Bacteriologic studies; organ system function (periodically during prolonged therapy)
• Hematologic: Hematopoietic function (periodically during prolonged therapy); white blood cell and differential cell counts (before starting and periodically during therapy)
• Hepatic: Hepatic function (periodically during prolonged therapy); serum bilirubin, AST, ALT, alkaline phosphatase, and GGT (at baseline and periodically during therapy, especially with high doses)
• Renal: Renal function in elderly patients; renal function (periodically during prolonged therapy); urinalysis, serum blood urea nitrogen, and creatinine (at baseline and periodically during therapy)

Patient advice:

• Avoid missing doses and complete the entire course of therapy.
• Contact physician as soon as possible if watery and bloody stools (with or without stomach cramps and fever) develop.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer