Metronidazole is an antibiotic used to fight bacteria in your body. Learn about side effects, interactions and indications. What Does Flagyl Treat? 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. Metronidazole is primarily used to treat: bacterial vaginosis, pelvic inflammatory disease (along with other antibacterials like ceftriaxone), pseudomembranous colitis, aspiration pneumonia, rosacea (topical), fungating wounds (topical), intra-abdominal infections, lung abscess, periodontal disease, amoebiasis, oral infections, giardiasis, trich. Metronidazole belongs to the class of medicines known as antibiotics. It works by killing bacteria or preventing their growth. However, this medicine will not work for colds, flu, or other virus infections. This medicine is available only with your doctor's prescription. 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. Flagyl (metronidazole) is a prescription antibiotic. It can treat bacterial and parasitic infections that affect the skin, gut, and other areas of the body. The best Flagyl dosage depends on what you need it for. Generally, adults are recommended to take 1 tablet (500 mg) by mouth 2 to 4 times a day for 7 to 10 days. Medscape - Amebiasis-specific dosing for Flagyl, Flagyl ER (metronidazole), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation schedules, and. Metronidazole, a nitroimidazole, exerts antibacterial effects in an anaerobic environment against most obligate anaerobes. Flagyl (Metronidazole) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Find patient medical information for Metronidazole (Flagyl, Likmez) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings.