Metronidazole

C. diff Risk

Low

Oral Bioavailability

Excellent

Approximate Cost

Dosing

Standard: 500mg IV/PO q12h Clostridium difficile and central nervous system infections: 500mg PO/IV q8h

Consider dose reduction with severe hepatic impairment (Child-Pugh C)

500mg IV q8-12h

General Information

Common Usage

Suspected or confirmed anaerobic infections including intra-abdominal, biliary, central nervous system, Clostridium difficile, Giardia and pelvic infections.

Also used in Crohns disease, bacterial vaginosis, and hepatic encephalopathy

Drug Monitoring

With prolonged therapy (>6wks) or if symptoms develop assess for peripheral/optic neuropathy

Adverse Effects

GI symptoms common- especially nausea/vomiting and metallic taste

Peripheral/optic neuropathy with extended therapy

Disulfiram-like reaction with alcohol (severe vomiting)

Rare neurotoxicity including aseptic meningitis and encephalopathy

Major Interactions

Ethanol- disulfiram-like reaction

Increases levels of cyclosporine, lithium, warfarin, and phenobarbital and phenytoin

Pharmacology

Antimicrobial class: Nitroimidazole

Pregnancy category: B

Average serum half life: 10.0

Biliary penetration: Therapeutic

CSF penetration: Therapeutic

Lung penetration: Therapeutic

Urine penetration: Poor