KI and kinact of erythromycin, clarithromycin, and verapamil obtained from the multiple time- and concentration-dependent inhibition assay with each CYP3A substrate
These parameters were determined as described under Materials and Methods (Data Analysis) based on the result shown in Fig. 2.
Inhibitor | Substrate | ||||
---|---|---|---|---|---|
Midazolam | Nifedipine | Testosterone | |||
Erythromycin | |||||
KI (μM) | 12.1 | 11.3 | 10.9 | ||
kinact (min-1) | 0.0215 | 0.0295 | 0.0352 | ||
Clarithromycin | |||||
KI (μM) | 15.5 | 15.9 | 12.9 | ||
kinact (min-1) | 0.0192 | 0.0244 | 0.0324 | ||
Verapamil | |||||
KI (μM) | 2.55 | 3.12 | 5.79 | ||
kinact (min-1) | 0.0277 | 0.0486 | 0.0591 |