Metronidazole

Activity

• anaerobes - inc. bacteroides fragilis

• Trichomonas vaginalis

• amoebiasis

• giardiasis

• NOT aerobes, facultative anaerobes

Mechanism of action

• reduction of nitro group by bacterial nitroreductase produces cytotoxic compounds (disrupts DNA)

Resistance

• decreased uptake
• elimination of cytotoxic compounds before interaction with DNA

Cautions

• alcohol
  • disulfiram-like reaction

Side Effects

• GI disturbance
  • nausea
  • vomiting
  • unpleasant taste
  • furred tongue
• rashes
  • erythema multiforme
  • pruritus
  • urticaria
• headache
• dizziness 
• ataxia
• abnormal liver function
  • darkening of urine
  • hepatitis
  • jaundice