Description
Omeprazole sulfone is the major metabolite of the gastric proton pump inhibitor, omeprazole (Item No.
14880). It is produced by cytochrome P450 (CYP)3A4 sulfoxidation of esomeprazole (Item No.
17326) and is found in plasma.
1 Omeprazole sulfone has been shown to act as a reversible direct-acting and metabolism-dependent inhibitor of CYP2C19 in pooled human liver microsomes (IC
50 = 18 μM).
2
in vivo
three hours after intake of 20 mg omeprazole only, the geometric mean plasma concentration of omeprazole sulfone were 106 nmol/l in 22 samples from subjects known to be extensive cyp2c19 metabolizers (em) and 672 nmol/l in the five subjects known to be poor cyp2c19 metabolizers (pm). the mean log10(omeprazole/omeprazole sulfone) ratio was 0.18 [4].
References
[1] nebert d w, russell d w. clinical importance of the cytochromes p450[j]. the lancet, 2002, 360(9340): 1155-1162.
[2] bel a, andersson t b, antonsson m, et al. stereoselective metabolism of omeprazole by human cytochrome p450 enzymes[j]. drug metabolism and disposition, 2000, 28(8): 966-972.
[3] nebert d w, russell d w. clinical importance of the cytochromes p450[j]. the lancet, 2002, 360(9340): 1155-1162.
[4] bttiger y. use of omeprazole sulfone in a single plasma sample as a probe for cyp3a4[j]. european journal of clinical pharmacology, 2006, 62(8): 621-625.
