IC50 values (μM) for inhibition of 2D6 activities in human liver microsomes
| Bufuralol 1′-Hydroxylase | ||
|---|---|---|
| Without NADPH | With NADPH | |
| Amlodipine | 57 | 88 |
| Diltiazem | >150 | >150 |
| Felodipine | 40 | 60 |
| Nicardipine | 2.8 | 3.5 |
| Nifedipine | 68 | >100 |
| Verapamil | 60 | 60 |
| Quinidine | 0.06 | 0.1 |
Incubations were performed in duplicate for each concentration of inhibitors by preincubation of inhibitors with or without NADPH for 30 min before adding the substrate.