Flagyl (metronidazole) is used to treat infections caused by anaerobic bacteria and parasites — organisms that thrive in low-oxygen environments. It is not effective against viral infections like colds or flu. Flagyl, Flagyl ER, and Flagyl Injection (metronidazole) are antimicrobial drugs used to treat bacterial vaginosis, trichomonas, amebiasis, and anaerobic bacterial infections. Learn about metronidazole (Flagyl) usage and dosing. Read the latest news and reviews about the drug as well as potential side effects and popular alternatives. Flagyl (metronidazole) is a prescription antibiotic used to treat anaerobic bacterial infections, trichomoniasis, and more. A common Flagyl dosage for adults is 1 tablet (500 mg) by mouth 2 to 4 times a day for 7 to 10 days. Metronidazole, sold under the brand name Flagyl and Metrogyl among others, is an antibiotic and antiprotozoal medication. [10] It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. [10] Flagyl (metronidazole) is an antibiotic that can help treat certain infections caused by bacteria or parasites that also cause diarrhea. It is not used to treat most cases of sudden (acute) diarrhea, such as viral “stomach flu” or mild food poisoning. It is also used to treat infections caused by protozoa (eg, trichomoniasis and amebiasis) and infections caused by bacteria that do not need oxygen to survive. The extended-release tablets are used to treat women with vaginal infections (bacterial vaginosis). Metronidazole belongs to the class of medicines known as antibiotics. Flagyl (metronidazole) is not usually used to treat a typical urinary tract infection (UTI), such as uncomplicated bladder infection (acute cystitis). Most uncomplicated UTIs are caused by aerobic bacteria like Escherichia coli that are not reliably covered by metronidazole. Medscape - Amebiasis-specific dosing for Flagyl, Flagyl ER (metronidazole), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation schedules, and. Find patient medical information for Metronidazole (Flagyl, Likmez) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings.