An antimicrobial drug particularly active against anaerobic (see ANAEROBE) bacteria and PROTOZOA. Given by mouth, by rectum or intravenously, it is used to treat infections of the urinary, genital, and digestive systems – for example, TRICHOMONIASIS, amoebiasis (see DYSENTERY), GIARDIASIS, and acute ulcerative GINGIVITIS, and is a useful treatment for dental abscesses. Topically, it is used in the management of ROSACEA and it reduces the odour produced by anaerobic bacteria in fungating tumours.