Description
Mechanism of Action
Metronidazole is converted to reduction products that interact with DNA to cause destruction of helical DNA structure and strand leading to a protein synthesis inhibition and cell death in susceptible organisms. It is effective against a wide range of organisms including E. histolytica, T. vaginalis, Giardia, anaerobes e.g. Bacterioides sp, Fusobacterium sp, Clostridium sp, Peptococcus sp and Peptostreptococcus sp, and moderately active against Gardnerella sp and Campylobacter sp.
Absorption: Readily absorbed from the GI tract (oral), poorly absorbed from the vagina (intravaginal); peak plasma concentrations after 1-2 hr (oral), 5-12 hr (rectal), 8 hr (intravaginal). May be delayed by the presence of food.
Distribution: Protein-binding: <20%. Widely distributed in body tissues and fluids e.g. bile, bone, breast milk, cerebral abscesses, CSF, liver and liver abscesses, saliva, semenal fluid, vaginal secretions (concentrations similar to those in plasma); crosses the placenta and rapidly enters fetal circulation.
Metabolism: Hepatic via side-chain oxidation and glucuronide formation.
Excretion: Mainly via urine (as metabolites); via faeces (small amounts). Elimination half-life: 8 hr; longer in neonates and severe hepatic impairment.
MIMS Class
Topical Antibiotics / Preparations for Vaginal Conditions / Other Antibiotics / Antiamoebics
ATC Classification
A01AB17 – metronidazole; Belongs to the class of local antiinfective and antiseptic preparations. Used in the treatment of diseases of the mouth.;
J01XD01 – metronidazole; Belongs to the class of imidazole derivative antibacterials. Used in the systemic treatment of infections.;
P01AB01 – metronidazole; Belongs to the class of nitroimidazole derivatives antiprotozoals. Used in the treatment amoebiasis and other protozoal diseases.;
G01AF01 – metronidazole; Belongs to the class of imidazole derivative antiinfectives. Used in the treatment of gynecological infections.;
D06BX01 – metronidazole; Belongs to the class of other topical chemotherapeutics used in the treatment of dermatological diseases
