Effect of cytochrome P450 inhibitors on the metabolism of cibenzoline enantiomers by human liver microsomes
| Inhibitor | Product Formation (% control) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| S(−)-Cibenzoline (5 μM) | R(+)-Cibenzoline (5 μM) | S(−)-Cibenzoline (100 μM) | R(+)-Cibenzoline (100 μM) | ||||||
| M2 | M3 | M4 | M1 | M2 | M3 | M4 | M2 | M2 | |
| Furafylline (1 μM) | 110 | 100 | 104 | 102 | 102 | 103 | 94 | NT | NT |
| Sulfaphenazole (100 μM) | 78 | 90 | 105 | 82 | 123 | 88 | 118 | NT | NT |
| Quinidine (10 μM) | 48 | 89 | 82 | <17 | 54 | 82 | 55 | 105 | 97 |
| Ketoconazole (2.5 μM) | <22 | 8 | 26 | 105 | <23 | <7 | <34 | 32 | 16 |
Cibenzoline enantiomers at 5 or 100 μM substrate concentration were incubated with human liver microsomes at 37°C for 30 min in the presence of NADPH generating system. Results represent mean of duplicate determinations.
NT, not tested.