C. diff Risk


Oral Bioavailability


Approximate Cost


Penicillin G: 12-24 million units/day IV in 6 divided doses

Penicillin VK: 300-600mg PO BID-QID

General Information

Common Usage

Pencillin G: Therapy of Streptococcal and other documented susceptible infections, syphilis

Penicillin VK: Streptococcal infections and therapy of documented susceptible infection not requiring parenteral therapy (i.e. upper respiratory tract), Prophylaxis after rheumatic fever

Drug Monitoring

Penicllin VK: Monitor for allergy. Periodic CBC, SCr

Adverse Effects

Penicillin G: Allergy/rash (immediate or delayed), seizures, cytopenias, eosinophilia, interstitial nephritis, abnormal liver enzymes, serum sickness

Penicillin VK: Allergy (anaphylaxis) and other rash, Cytopenias, Positive Coombs, Eosinophilia, Serum sickness, AIN

Major Interactions

No significant


Antimicrobial class: Penicillin

Pregnancy category: B

Average serum half life: 1.0

Biliary penetration: Therapeutic

CSF penetration: Moderate

Lung penetration: Therapeutic

Urine penetration: Therapeutic