Metronidazole
Metronidazole is a nitroimidazole antimicrobial used to treat bacterial vaginosis. The one product listed here is Flagyl Er, available as 200 mg and 400 mg extended-release tablets.
Key points
- Beyond vaginal infections, metronidazole treats trichomoniasis, amebiasis, giardiasis, and other anaerobic bacterial infections throughout the body.
- Flagyl Er is the extended-release form, releasing the medicine over a longer period so levels stay steady rather than peaking and falling.
- Metronidazole carries a boxed warning that it may cause cancer in laboratory animals, though follow-up studies in treated patients have not shown increased cancer incidence.
How does Metronidazole work?
Metronidazole enters the bacteria or parasite and disrupts its DNA. Once the genetic material is damaged, the organism can no longer produce the proteins it needs to survive, and it dies. Flagyl Er is the extended-release form, so the medicine is released over a longer period rather than all at once. It is listed here under Women’s Health for bacterial vaginosis, though metronidazole works against bacteria that thrive without oxygen and against certain parasites elsewhere in the body.