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.

See also:

Further information

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