• Bacterial infections

Pfizerpen Generic Name & Formulations

General Description

Penicillin G potassium 5million Units, 20million Units (IV infusion only); per vial; pwd for IM, IV, intrapleural, intrathecal inj after reconstitution; contains sodium 6.8mg, potassium 65.6mg; per 1million Units.

Pharmacological Class


How Supplied

Vials (5million Units)—10; 20million Units—1


Pfizerpen Indications


Susceptible severe infections where rapid and high penicillin levels are required (see literature).

Pfizerpen Dosage and Administration

Adults and Children

Bacteremia, pneumonia, endocarditis, pericarditis, empyema, meningitis, other severe infections (due to streptococci, pneumococci, staphylococci): minimum of 5million Units per day. Syphilis: dosage and duration determined by age of patient and stage of disease. Gonorrheal endocarditis: minimum 5million Units per day. Meningococcic meningitis: 1–2million Units IM every 2 hours, or continuous IV drip of 20–30million Units/day. Actinomycosis: 1–6million Units/day for cervicofacial cases; 10–20million Units/day for thoracic and abdominal disease. Clostridial infections: 20million Units/day as adjunctive therapy to antitoxin. Fusospirochetal infections: severe infections of oropharynx, lower respiratory tract, and genital area: 5–10million Units/day. Rat-bite fever: 12–15million Units/day for 3–4 weeks. Listeria infections: Neonates: 500,000–1million Units/day. Adults with meningitis: 15–20million Units/day for 2 weeks. Adults with endocarditis: 15–20million Units/day for 4 weeks. Pasteurella infections: Bacteremia and meningitis: 4–6million Units/day for 2 weeks. Ersipeloid: Endocarditis: 2–20million Units/day for 4–6 weeks. Gram-negative bacillary infections: Bacteremia: 20–80million Units/day. Diphtheria (carrier state): 300,000–400,000 Units/day in divided doses for 10–12 days. Anthrax: a minimum of 5million Units/day in divided doses until cure is effected. See literature re: prophylaxis of bacterial endocarditis in dental procedures.

Pfizerpen Contraindications

Not Applicable

Pfizerpen Boxed Warnings

Not Applicable

Pfizerpen Warnings/Precautions


Cephalosporin, imipenem, or other allergy: not recommended. Asthma. Electrolyte imbalance possible with rapid IV infusion; infuse slowly and monitor electrolytes frequently. Monitor renal, hepatic and hematopoietic function with long-term therapy. Newborns. Infants. Pregnancy (Cat.B). Nursing mothers.

Pfizerpen Pharmacokinetics

See Literature

Pfizerpen Interactions


Bacteriostatic antibiotics (eg, erythromycin, tetracycline) may diminish bactericidal effects. Potentiated by probenecid. May cause positive Coombs test.

Pfizerpen Adverse Reactions

Adverse Reactions

Rash, drug fever, serum sickness, anaphylaxis, blood dyscrasias, neuropathy, nephropathy, inj site reactions.

Pfizerpen Clinical Trials

See Literature

Pfizerpen Note

Not Applicable

Pfizerpen Patient Counseling

See Literature