Table 2.
Pharmacokinetic parameters of omeprazole, 5-hydroxyomeprazole and the sulphone metabolite after a single oral 40-mg dose of omeprazole to 16 healthy volunteers
| Units | CYP2C19*1/*1 Mean (95% CI) | CYP2C19*17/*17 Mean (95% CI) | P-value | |
|---|---|---|---|---|
| Omeprazole | ||||
| AUC∞ | nmol h l−1 | 4151 (2084, 6218) | 1973 (1476, 2469) | 0.04* |
| CL | l h−1 | 48 (22, 75) | 61 (44, 77) | 0.37† |
| Tmax | h | 2.1 (1.2, 3.1) | 2.1 (1.1, 3.1) | 0.95 |
| Cmax | nmol l−1 | 2109 (1169, 3049) | 1447 (1069, 1825) | 0.16 |
| λΖt1/2 | h | 1.2 (0.9, 1.5) | 0.9 (0.6, 1.2) | 0.18 |
| 5-Hydroxyomeprazole | ||||
| AUC∞ | nmol h l−1 | 3359 (2803, 3915) | 2989 (2273, 3706) | 0.33 |
| Tmax | h | 2.4 (1.2, 3.7) | 2.1 (1.1, 3.1) | 0.65 |
| Cmax | nmol l−1 | 1534 (1081, 1988) | 1527 (1234, 1819) | 0.97 |
| λΖt1/2 | h | 1.3 (0.9, 1.6) | 1.1 (1.0, 1.3) | 0.33 |
| Omeprazole sulphone | ||||
| AUC∞ | nmol h l−1 | 3343 (1301, 5384) | 1083 (690, 1476) | 0.03* |
| Tmax | h | 2.6 (1.4, 3.8) | 2.2 (1.3, 3.1) | 0.54 |
| Cmax | nmol l−1 | 563 (362, 765) | 336 (239, 433) | 0.04* |
| λΖt1/2 | h | 3.3 (1.7, 4.8) | 1.9 (1.4, 2.4) | 0.09 |
| OME AUC∞/5-OH AUC∞ | 1.2 (0.70, 1.6) | 0.66 (0.54, 0.79) | 0.04* | |
†
The lack of statistical significance, despite significant differences in AUC∞ values, is due to the transformation of AUC∞ values inherent in the calculation of clearance, CL = dose
*
(1/AUC∞). CYP2C19*17/*17 (n = 5) and CYP2C19*1/*1 (n = 11) groups were compared with an unpaired two-tailed heteroscedastic t-test. Asterisks denote P-values < 0.05. Values are means with 95% confidence interval in parentheses.