C. diff Risk


Oral Bioavailability


Approximate Cost

IV-$3/d PO-$1/d

Spectrum Of Activity


Dosage adjustment in severe renal impairment only. Consult with a pharmacist for renal dosing

General Information

Common Usage

  • Suspected or confirmed anaerobic infections including intra-abdominal, biliary, central nervous system,

  • Clostridium difficile, Giardia and gynecoogical infections

  • Also used in Crohn's disease and bacterial vaginosis.

Drug Monitoring

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

Adverse Effects

  • GI symptoms common- especially nausea and vomiting and metallic taste

  • Peripheral and or optic neuropathy with extended therapy

  • Disulfiram-like reaction (severe vomiting)

  • Rare neurotoxicity including aseptic meningitis and encephalopathy

Major Interactions

Disulfiram reaction wtih alcohol or alcohol-containing medications/products.

Oral Liquids

Concentration: 50 mg/mL (compounded)
Taste: less palatable, unpleasant taste
Not all strengths of oral liquids are listed nor are available on IWK formulary

Tablet/Capsule Strengths

250 mg tablet
Tablets and capsules are preferred especially over an unpleasant tasting liquid.
Not all strengths of oral tablets/capsules are listed and they are not all available on the IWK formulary.


Antimicrobial class: Nitroimidazole

Average serum half life:

  • Neonates <7 days: (prolonged with lower GA) 24.8-75.3 hours.

  • Neonates ≥7 days: ~22.5 hours

  • Children and adolescents: 6-10 hours.

  • Adults: 8 hours

Route of Elimination:

  • urine (unchanged drug and metabolites: 60-80%; ~20% of total as unchanged drug)

  • feces (6-15%)