5-hydroxy Omeprazole is a major metabolite of omeprazole , an inhibitor of the gastric H+/K+-ATPase pump.[1] 5-hydroxy Omeprazole is produced from omeprazole by the action of cytochrome P450 (CYP) isoform 2C19, a monooxygenase. [2][3] CYP2C19 polymorphisms significantly influence the metabolism of omeprazole, and individuals may be classified as homozygous extensive metabolizers, heterozygous extensive metabolizers, and poor metabolizers.[1]
Reference:
[1]. Shi, S., and Klotz, U. Proton pump inhibitors: An update of their clinical use and pharmacokinetics. Eur. J. Clin. Pharmacol. 64(10), 935-951 (2008).
[2]. Abelö, A., Andersson, T.B., Antonsson, M., et al. Stereoselective metabolism of omeprazole by human cytochrome P450 enzymes. Drug Metab. Dispos. 28(8), 966-972 (2000).
[3]. Karam, W.G., Goldstein, J.A., Lasker, J.M., et al. Human CYP2C19 is a major omeprazole 5-hydroxylase, as demonstrated with recombinant cytochrome P450 enzymes. Drug Metab. Dispos. 24, 1081-1087 (1996).