It works by stopping the growth of certain bacteria and parasites. This antibiotic treats only certain bacterial and parasitic infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections. FLAGYL (metronidazole) tablets contain 250 mg or 500 mg of metronidazole. Inactive ingredients include cellulose, FD&C Blue No. 2 Lake, hydroxypropyl cellulose, hypromellose, polyethylene. Do not take Flagyl: if you are allergic to metronidazole, to any medicine in the imidazole group (the group of antibiotics that includes metronidazole) or to any other ingredient of this medicine listed in Section 6. 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 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) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Flagyl is used to treat bacterial infections of the vagina, stomach, skin and joints. Learn about side effects, interactions and indications. Find patient medical information for Metronidazole (Flagyl, Likmez) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Medscape - Amebiasis-specific dosing for Flagyl, Flagyl ER (metronidazole), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation schedules, and. Recommended Regimens for Bacterial Vaginosis A review regarding alcohol consumption during metronidazole treatment reported no in vitro studies, animal models, reports of adverse effects, or clinical studies providing convincing evidence of a disulfiram-like interaction between alcohol and metronidazole (1011).