Flagyl 400 Tablet is used to treat and prevent bacterial and parasitic infections including blood, brain, bone, lung, stomach lining, pelvic area and genital infections, amoebiasis, gum and teeth infections, infected leg ulcers or pressure sores, stomach ulcers caused by Helicobacter pylori, urinary or genital infections caused by Trichomonas parasite. Furthermore, it can also be used to treat infections following childbirth or in a wound following an operation. It contains Metronidazole, which stops the growth of infection-causing bacteria or parasites. It may cause common side effects such as nausea, vomiting, upset stomach, loss of appetite, dry mouth, and metallic taste. Before taking this medicine, you should tell your doctor if you are allergic to any of its components or if you are pregnant/breastfeeding, and about all the medications you are taking and pre-existing medical conditions.