Inhibition of CYP2C19 in human liver microsomes by omeprazole, its enantiomers, or its major metabolites and lansoprazole and pantoprazole
| Compound | IC50 (μM)a | IC50 Shift (fold)b | ||
|---|---|---|---|---|
| No Preincubation | 30-Min Preincubation (−NADPH) | 30-Min Preincubation (+NADPH) | ||
| Omeprazole | 6.9 ± 0.7 | 8.7 ± 0.6 | 1.7 ± 0.0 | 4.2 |
| Esomeprazole | 15 ± 1 | 16 ± 1 | 1.5 ± 0.1 | 10 |
| R-Omeprazole | 8.1 ± 1.2 | 12 ± 1 | 3.3 ± 0.4 | 2.5 |
| Omeprazole sulfide | 9.7 ± 0.5 | 8.4 ± 2.7 | 9.6 ± 1.0 | 1.0 |
| Omeprazole sulfone | 18 ± 2 | 12 ± 3 | 5.6 ± 0.5 | 3.2 |
| 5-Hydroxyomeprazole | >100 | >100 | >100 | NA |
| Lansoprazole | 1.2 ± 0.1 | 1.2 ± 0.1 | 1.2 ± 0.0 | 1.0 |
| Pantoprazole | 93 ± 7 | >100 | 65 ± 4 | 1.4 |
NA, not applicable (i.e., IC50 values greater than the highest concentration examined).
↵a Values are displayed to two significant figures ± S.E. of the measurement.
↵b Calculated from full precision values as (IC50 with no preincubation)/(IC50 with 30-min preincubation + NADPH) and rounded to two significant figures. IC50 shifts >1.5-fold appear in bold.