Table 3.
Pharmacokinetic parameter estimates of omeprazole and its two main metabolites after a single oral 40-mg dose of omeprazole to two groups of healthy volunteers with distinct CYP2C19 homozygous genotypes [15]
| Mean (95% CI) CYP2C19*1/*1 | Mean (95% CI) CYP2C19*17/*17 | |
|---|---|---|
| Parameter compound (nmol h−1 l−1) | n= 11 | n= 5 |
| AUC∞ omeprazole (OME) | 4151 (2084–6218) | 1973 (1476–2469) |
| AUC∞ 5-hydroxyomeprazole (5-OH) | 3359 (2803–3915) | 2989 (2273–3706) |
| AUC∞ omeprazole sulphone | 3343 (1301–5384) | 1083 (690–1476) |
| AUC∞ OME/ AUC∞ 5-OH (dimensionless) | 1.2 (0.70–1.6) | 0.66 (0.54–0.79) |
The omeprazole metabolic ratio was also not discriminative, an observation consistent with the data first reported with the discovery of the CYP2C19*17 allele (Figure 2).