Effect of preincubation with efavirenz on the bupropion and cyclosphosphamide hydroxylation activities of P450 2B6 The P450s were reconstituted with reductase as described under Materials and Methods. The primary reaction mixture contained the concentrations of efavirenz indicated. NADPH was added to the primary reaction mixture to initiate the reaction.
Primary Reaction Conditions | Percentage of Control Activity Remaining | ||
|---|---|---|---|
| Bupropion | Cyclophosphamide | ||
| – NADPH + 10 μM efavirenz | 100 | 100 | |
| + NADPH + 10 μM efavirenz | 62 ± 3 | 67 ± 5 | |
| – NADPH + 20 μM efavirenz | 100 | 100 | |
| + NADPH + 20 μM efavirenz | 45 ± 2 | 42 ± 4 | |