Flagyl S is a prescription medication used to treat bacterial infections caused by certain types of microorganisms. It is commonly used to treat the following infections: Amebiasis, intestinal or extraintestinal, Bacterial vaginosis, Balantidiasis, Clostridioides difficile infection, treatment, Dientamoeba fragilis infection, Giardiasis, Helicobacter pylori eradication, Intra-abdominal infection, Intracranial abscess, Odontogenic infection, Pneumonia, aspiration, Pouchitis, acute, Sexually transmitted infections, Skin and soft tissue infection, Surgical prophylaxis, Tetanus It contains metronidazole, an antibiotic and antiprotozoal medication that kills or stops the growth of bacteria and other microorganisms. Metronidazole is incorporated into the DNA and causes the double-helix structure to unwind, preventing replication. Fact Table Formula C6H9N3O3 License US DailyMed, US FDA Bioavailability 80% Legal status Rx-Only Chemical Name Metronidazole Elimination half-life 8 hours Dosage (Strength) 200mg / 5ml 100ml Pregnancy Consult Doctor Brands Flagyl-S Protein binding 20% PubChem CID 4173 MedlinePlus a689011 ChEBI 6909 ATC code A01AB17 DrugBank A01AB17 KEGG D00409 Routes of administration Oral