Metronidazole (MNZ), marketed under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication.[3] It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. It is effective for dracunculiasis, giardiasis, trichomoniasis, and amebiasis.[3] It is the drug of choice for a first episode of mild-to-moderate Clostridium difficile colitis.[4] Metronidazole is available by mouth, as a cream, and intravenously.[3]

Starting at
| 2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethanol |
| Pronunciation | /mɛtrəˈnaɪdəzoʊl/ |
| Trade names | Flagyl, Metro, others |
| AHFS/Drugs.com | monograph |
| Licence data | US FDA:link |
| Pregnancy category |
AU: B2 US: B (No risk in non-human studies) |
| Legal status |
AU: S4 (Prescription only) CA: ℞-only UK: POM (Prescription only) US: ℞-only |
| Routes of administration |
oral, topical, rectal, IV, vaginal |
| Bioavailability | 80% (oral), 60-80% (rectal), 20-25% (vaginal)[1][2] |
| Protein binding | 20%[1][2] |
| Metabolism | Hepatic[1][2] |
| Biological half-life | 8 hours[1][2] |
| Excretion | Urine (77%), faeces (14%)[1][2] |
| CAS Number | 443-48-1 |
| ATC code | A01AB17 , D06BX01, G01AF01, J01XD01, P01AB01, QP51AA01 |
| PubChem | CID: 4173 |
| DrugBank | DB00916 |
| ChemSpider | 4029 |
| UNII | 140QMO216E |
| KEGG | D00409 |
| ChEBI | CHEBI:6909 |
| ChEMBL | CHEMBL137 |
| NIAID ChemDB | 007953 |
| Formula | C6H9N3O3 |
| Molecular mass | 171.15 g/mol |
|
InChI[show] |
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| Melting point | 159 to 163 °C (318 to 325 °F) |