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. 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. Learn about the side effects of metronidazole, from common to rare, for consumers and healthcare professionals. Metronidazole (Flagyl) is a medication that treats infections caused by bacteria or parasites. You can take this tablet or capsule by mouth. Metronidazole is used to treat certain infections in the body caused by bacteria including sexually transmitted diseases (STDs) and bacterial vaginosis (an infection caused by too much of certain types of harmful bacteria in the vagina) in women. Metronidazole is a prescription antibiotic medication prescribed for the treatment of a variety of parasitic and bacterial infections of the vagina, gynecological area, skin, intra-abdominal cavity, blood, bone, joint, nervous system, and heart. Metronidazole is a nitroimidazole antimicrobial that kills anaerobic bacteria and parasites via DNA-damaging free radicals. It treats trichomoniasis, amebiasis, and serious anaerobic infections, and prevents post-colorectal-surgery infection. Learn about side effects, interactions, and indications. Metronidazole is used to treat a certain type of vaginal infection (bacterial vaginosis) in women who are not pregnant. Learn about side effects, drug interactions, dosages, warnings, and more. Metronidazole oral tablets are prescription drugs used to treat infections caused by bacteria or parasites. The immediate-release tablet comes as a generic drug and the brand-name drug Flagyl. Find patient medical information for Metronidazole (Flagyl, Likmez) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings.