Infectious Disease Compendium

Ampicillin (Omnipen®)


CrCl Formula

CrCl > 80: 500 mg - 2 gm IV q 4-6 h.

CrCl 80-50: 500 mg - 2 gm IV q 4-6 h.

CrCl 50-10: 500 mg - 2 gm IV q 8 h.

CrCl < 10: 500 mg - 2 gm IV q 12 h.

Hemodialysis: 500 mg - 2 gm after HD.

Peritoneal dialysis: 1 - 4 g after PD.

Obesity dosing

Important side effects

Important drug interactions

Rants and Screeds


Causes a rash with acute mono, probably more sensitive and specific than a monospot.

Treatment of choice

Enterococcus, Listeria.

Use for

Any Streptococci (all). Actinomyces, Anthrax, bacterial Endocarditis prophylaxis, Borrelia burgdorferi infection (Lyme), bronchiectasis, Bronchitis, Chancroid, Chlamydia infections, COPD exacerbation, Endocarditis, endodontic therapy, prophylaxis, Enteric fever, Neisseria, Haemophilus influenzae, Helicobacter pylori, Leptospira infections, Lyme Disease, Meningitis, Otitis media, periodontal disease, Pharyngitis, Pneumonia, Shigella, Sinusitis acute, Cellulitis, Typhoid fever, UTI, Whipples disease.

Don't use for