Nimodipine: Drug Metabolism and Pharmacokinetic Profile

Publisher Summary Nimodipine is a dihydropyridine calcium channel blocker derivative, which is used in the treatment of cerebrovascular disorders. Nimodipine is rapidly absorbed from the gastrointestinal tract following oral administration, but undergoes extensive first-pass metabolism in the liver. Nimodipine is extensively metabolized in the liver and undergoes extensive first-pass metabolism. More than 18 metabolites have been detected and identified from the biotransformation of nimodipine. The drug undergoes different reactions before its excretion. These reactions include, dehydrogenation of the 1,4-dihydropyridine moiety, oxidation of the two ester groups, and oxidative demethylation, which is followed by carboxylic acid formation via oxidation of the resulting alcohol. Nimodipine is excreted in feces via the bile duct and in urine via the glomular filtration, as metabolites. Fecal excretion is the major excretory route (greater than 67%). The parent compound and its metabolites are detected in breast milk. Because of the cycle of excretion/reabsorption, the plasma concentration decreases and increases. More than 80% and 90% of the reabsorbed quantity is excreted via bile and urine, respectively.