Penicillin G Aqueous (Pfizerpen)

Category:

• Antibiotic

Description:

• Penicillin, Natural

Indications:

• Meningococcal menigitis/septicemia

• Actinomycosis

• Clostridial infections (botulism, gas gangrene and tetanus)

• Fusopirochetal infections

• Rat-bite fever

• Listeria infections

• Pasteurella infections

• Erysipeloid endocarditis

• Diphtheria (adjunct to antitoxin to prevent carrier state)

• Anthrax

• Serious streptococcal infections

• Syphilis (neurosyphilis)

• Disseminated gonococcal infections

• Lyme disease (non-FDA approved indication)

Contraindications:

• None

Precautions:

• Pregnancy category B

• Use with caution in patients with penicillin or cephalosporin allergy (5-10% chance of cross-reactivity)

• Counsel patient to finish all medication to prevent development of resistance

• Intramuscular injection or continuous IV infusion are preferred routes of administration

• Dosage modifications are generally only required in patients with severe renal impairment

Adverse Reactions (Side Effects):

• Hypersensitivity

• Gastrointestinal: nausea, vomiting, diarrhea

• Vaginitis

Dosage:

Administered by injection (available in powder for injection and premixed/frozen)

• Meningococcal menigitis/septicemia:

  • Adult: 24 million units per day (1-2 million units q2h)

  • Adult: 200,000-300,000 units/kg/day q2-4h in divided doses for 24 doses total

  • Children: 250,000 units/kg/day divided equally q4h for 7-14 days

• Actinomycosis:

  • cervicofacial cases: 1-6 million units per day

  • thoracic/abdominal cases: 10-20 million units/day IV q4-6h for 6 weeks

• Clostridial infections

  • 20 million units/day q4-6h

• Fusopirochetal infections

  • 5-10 million units/day q4-6h

• Rat-bite fever

  • Adult: 12-20 million units/day q4-6h for 3-4 weeks

  • Children: 150,000-250,000 units/kg/day divided equally q4h for 4 weeks

• Listeria infections

  • 15-20 million units/day q4-6h for 2 weeks (menigitis) or 4 weeks (endocarditis)

• Pasteurella infections

  • 4-6 million units/day q4-6h for 2 weeks

• Erysipeloid endocarditis

  • 12-20 million units/day q4-6h for 4-6 weeks

• Diphtheria

  • Adult: 2-3 million units/day q4-6h for 10-12 days

  • Children: 150,000-250,000 units/kg/day divided equally q6h for 7-10 days

• Anthrax

  • minimum of 5 million units/day, may go up to 12-20 million units/day

• Serious streptococcal infections

  • Adult: 5-24 million units/day q4-6h

  • Children: 150,000 units/kg/day divided equally q4-6h

• Syphilis

  • 18-24 millions units/day (3-4 million units q4h) for 10-14 days

• Disseminated gonococcal infections

  • Adult: 10 million units/day q4-6h

  • Children (<45 kg):

    • arthritis: 100,000 units/kg/day divided into 4 equal doses for 7-10 days

    • menigitis: 250,000 units/kg/day divided equally q4h for 10-14 days

    • endocarditis: 250,000 units/kg/day divided equally q4h for 4 weeks

  • Children (>45 kg):

    • arthritis, menigitis, endocarditis: 10 million units/day divided into 4 equal doses for duration of therapy

• Lyme disease

  • use oral penicllin V for erythema chronicum migrans

  • 200,000-300,000 units/kg/day IV for 10-14 days