Metronidazole selectively blocks some of the functions within the bacterial cells and the parasites resulting in their death. Metronidazole selectively blocks some of the functions within the bacterial cells and the parasites resulting in their death. When administered systemically via oral tablets, Metronidazole works by inhibiting bacterial DNA synthesis hence preventing the replication of bacteria. Metronidazole antibiotic renders good services in many areas. Metronidazole should be used with caution in patients with active or chronic severe peripheral and central nervous system diseases due to the risk of neurological aggravation. Metronidazole is used alone or in combination with other antibiotics in treating abscesses in the liver, pelvis, abdomen and brain caused by susceptible anaerobic bacteria. Metronidazole antibiotic renders good services in many areas.