Penicillin G Procaine
General
- Type: Natural Penicillin
- Routes of Administration: IM
- Common Trade Names:
Adult Dosing
Anthrax
- Inhalational (Postexposure Prophylaxis)
- 1,200,000 units IM q12 hours x 60 days (see below)
- Info: Total treatment duration = 60 days. Do not give IM for over 2 weeks, switching alternative treatment to complete course
- Cutaneous, Nonsevere (Treatment)
- 600,000-1,200,000 units/day IM
Endocarditis by susceptible Streptococcus viridans
- 1.2 million units IM q6 hours x 2-4 weeks + aminoglycoside
Neurosyphilis
- 2.4 million units/day IM + 500mg probenecid PO QID x 10-14 days
- Info: Penicillin G aqueous I.V. is preferred
Whipple's Disease
- 1.2 million units/day + streptomycin x 10-14 days
- Followed by trimethoprim/sulfamethoxazole or doxycycline x 1 year
Pediatric Dosing
Avoid use in neonates: increased risk of sterile abscesses and procaine reactions
General
- 25,000-50,000 units/kg/day divided 1-2 times/day
- First Dose: 25,000-50,000 units/kg x 1
- Max: 4.8 million units/day
Anthrax
- Inhalational (postexposure prophylaxis)
- 25,000 units/kg IM q12 hours
- Max: 1,200,000 units q12 hours
- Info: Total treatment duration = 60 days. Do not give IM for over 2 weeks, switching alternative treatment to complete course
Syphilis (Congenital)
- 50,000 units/kg/day IM daily x 10 days
- If >1 day of therapy is missed, restart entire course of treatment
Special Populations
- Pregnancy Category: B
- Lactation: Use caution
- Renal Dosing
- Adult
- Pediatric
- Hepatic Dosing
- Adult
- Pediatric
Contraindications
- Allergy to class/drug
- Avoid use in neonates
Adverse Reactions
Serious
- Procaine reactions: Immediate toxic reactions, particularly when a large single dose is administered (4.8 million units); mental disturbances including anxiety, confusion, agitation, depression, weakness, seizures, hallucinations, combativeness, and fear
- Jarisch-Herxheimer reaction with syphilis treatment
- Pseudomembranous colitis
Common
- Rash, urticaria, exfoliative dermatitis
- Serum-sickness like reaction
Pharmacology
- Half-life: 30m
- Metabolism: Hepatic
- Excretion: Urinary
- Mechanism of Action: Bactericidal; Interferes with cell wall mucopeptide synthesis during active multiplication