RiteMED Metronidazole Mechanism of Action

Amebicide/Antiprotozoal.
Pharmacology: Metronidazole is a 5-nitro-imidazole derivative with activity against anaerobic bacteria and protozoa. Metronidazole is readily absorbed following administration by mouth and bioavailability approaches 100%. Peak plasma concentrations of approximately 5 and 10 mcg per mL are achieved, usually within 1 to 2 hours, after single doses of 250 and 500 mg respectively.
Metronidazole is widely distributed. It appears in most body tissues and fluids including bile, bone, breast milk cerebral abscesses, cerebrospinal fluid, liver and liver abscesses, saliva, seminal fluid, and vaginal secretions, and achieves concentrations similar to those in plasma. It also crosses the placenta and rapidly enters the fetal circulation. No more than 20% is bound to plasma proteins.
Metronidazole is metabolized in the liver by side chain oxidation and glucuronide formation. The elimination half-life of Metronidazole is about 8 hours; that of the hydroxy metabolite slightly longer. The half-life of Metronidazole is reported to be longer in neonates and in patients with severe hepatic impairment; that of the hydroxy metabolite is prolonged in patients with substantial renal impairment. The majority of the dose of Metronidazole is excreted in the urine, mainly as metabolites; a small amount appears in the feces.