Metronidazole Treatment for Infectious Diarrhea

Dosage Recommendations

• The Infectious Diseases Society of America recommends metronidazole 250-750 mg three times daily for 7-10 days as a second-line treatment for Giardia lamblia after tinidazole 1, 2
• For Clostridium difficile, the Infectious Diseases Society of America recommends metronidazole 500 mg three times daily for 10 days as a second-line treatment when access to vancomycin or fidaxomicin is limited 3, 4
• The Infectious Diseases Society of America recommends metronidazole 250 mg four times daily to 500 mg three times daily for 10 days for non-severe CDI only 2, 5

Administration Considerations

• Intravenous metronidazole can be used at 500 mg every 8 hours for severe infections where oral administration is not possible 6, 7

Important Caveats

• The Infectious Diseases Society of America advises against the use of antimotility agents when treating infectious diarrhea 5
• The Infectious Diseases Society of America recommends avoiding metronidazole for most bacterial causes of diarrhea other than C. difficile, due to preferred antibiotics based on susceptibility patterns 1
• Prolonged use of metronidazole increases the risk of peripheral neuropathy 4