Benzimidazole is also a privileged scaffold of many drugs such as omeprazole, rabeprazole, lansoprazole, dexlansoprazole, pantoprazole, esomeprazole (proton pump inhibitors), mebendazole (antihelmentic), albendazole (antimicrobial), and
astemizole (antihistaminic) [26-28],
Henceforth, this preclinical study was undertaken to compare the sedative property of fexofenadine, a newer the second-generation antihistaminic with terfenadine,
astemizole, and cetirizine in albino rats using potentiation of phenobarbitone sleep time model.
Bober, "Chromatographic analysis of
astemizole. Trends in Chromatogr," in K.
Danazol [11], decursin [14], hydroxyebastine [24], thelephoric acid [21], telmisartan [17], TSAHC [11] inhibited CYP2J2-mediated
astemizole O-demethylation activity with [IC.sub.50] values of 0.02, 6.95, 1.50, 3.23, 0.42, and 2.60 [micro]M, respectively.
In vitro studies have shown ketoconazole, a potent inhibitor of CYP3A4 activity, to be at least 100 times more potent than paroxetine as an inhibitor of the metabolism of several substrates for CYP3A4, including
astemizole, triazolam, and cyclosporine.
Benzimidazole is an interesting heterocyclic ring system because it is present in naturally occurring cyanocobalamin and several known commercialized drugs such as mebendazole,
astemizole, and emedastine difumarate.
The two compounds are already marketed as the drugs tacrolimus and
astemizole.