Spectrum Of Activity

General Information

Suspected or confirmed anaerobic infections including:

  • Intra-abdominal
  • Biliary
  • Central nervous system
  • Clostridium difficile
  • Giardia
  • Pelvic infections

Also used in:

  • Crohn's disease
  • Bacterial vaginosis
  • Hepatic encephalopathy

Black Box Warning: Metronidazole has been shown to be carcinogenic in mice and rats. Its use should be reserved only for conditions for which it is approved.

Assess for peripheral/optic neuropathy with prolonged therapy (>6 weeks) or if symptoms develop.


  • Nausea
  • Diarrhea
  • Abnormal taste in mouth
  • Headache
  • Dizziness
  • Candida infection of genital region
  • Vaginal discharge/irritation
  • Vaginitis


  • Stevens-Johnson syndrome
  • Toxic epidermal necrolysis
  • Leukopenia
  • Hepatic failure (acute)
  • Hepatotoxicity
  • Aseptic meningitis
  • Encephalopathy
  • Peripheral neuropathy
  • Seizure
  • Disorder of optic nerve
  • Ototoxicity
  • Hemolytic uremic syndrome
  • Ethanol:Disulfiram-like reaction

Increases levels of:

  • Cyclosporine
  • Lithium
  • Warfarin
  • Phenobarbital
  • Phenytoin

Antimicrobial class: Nitroimidazole

Pregnancy category: B

Average serum half life: 10 hours

Biliary penetration: Therapeutic

CSF penetration: Therapeutic

Lung penetration: Therapeutic

Urine penetration: Poor