Brand Names:
Flagyl, Protostat, Nitroimidazole

Drug Type: Antibiotic, Antiprotozoal, Anthelmintic, Antiinflammatory


Metronidazole (brand name Flagyl®) is a synthetic, nitroimidazole antibacterial and antiprotozoal agent. It is used to treat bacterial infections caused by anaerobic bacteria (such as Clostridium), and Giardia and other gastrointestinal protozoal flagellates.

Storage/Stability: Metronidazole tablets and HCl powder for injection should be stored at temperatures less than 30°C and protected from light. The injection should be protected from light and freezing and stored at room temperature.

Toxicity: The oral LD50 of metronidazole in rats is 5000 mg/kg.
  • 10-50 mg/kg PO q12-24h
available as tablets (250 or 500 mg) to be given orally or as an injectable solution (5 mg/mL) for IM administration. Resistant organisms may require two daily injections followed by two more doses repeated in 14 days.
  • Diarrhea
  • Vision problems
  • Behavioral changes
  • Atropine: The risk or severity of QTc prolongation can be increased when Metronidazole is combined with Atropine.
  • Meloxicam: The risk or severity of methemoglobinemia can be increased when Metronidazole is combined with Meloxicam.