Table 2.
Mean % contribution of individual CYPs to oxidative metabolism determined using average % content (APC) and relative activity factor (RAF) methods
| Percentage contribution | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| CYP1A2 | CYP2C9 | CYP2C19 | CYP2D6 | CYP3A4 | ||||||
| Compound | APC | RAF | APC | RAF | APC | RAF | APC | RAF | APC | RAF |
| Phenacetin | 44 | 58 | 5 | 4 | 22 | 14 | 2 | 3 | 27 | 21 |
| Naproxen* | 49 | 28 | 50 | 71 | 1 | 2 | – | – | – | – |
| Diclofenac | – | – | 100 | 100 | – | – | – | – | – | – |
| Omeprazole | – | – | – | – | 68 | 60 | – | – | 32 | 40 |
| Bufuralol | – | – | – | – | – | – | 100 | 100 | – | – |
| Metoprolol | – | – | – | – | – | – | 100 | 100 | – | – |
| Propranolol | 26 | 27 | – | – | 15 | 6 | 59 | 67 | – | – |
| Diltazem | – | – | – | – | 6 | 5 | – | – | 94 | 95 |
| Verapamil | – | – | – | – | – | – | – | – | 100 | 100 |
| Tolbutamide | – | – | 70 | 72 | 30 | 28 | – | – | – | – |
| Dextromethorphan | – | – | – | – | 14 | 10 | 86 | 90 | – | – |
| Testosterone | – | – | – | – | – | – | – | – | 100 | 100 |
| Diazepam* | – | – | – | – | 94 | 95 | – | – | 6 | 5 |
| Ibuprofen* | – | – | 90 | 91 | 10 | 9 | – | – | – | – |
*
Original raw data taken from [3] or [5]. APC and RAF values represent mean derived from three individual experiments. Naproxen provided a RAF for tolbutamide CYP2C9 (45 pmol mg−1), metoprolol for dextromethorphan CYP2D6 (6 pmol mg−1) and verapamil for testosterone CYP3A4 (98 pmol mg−1). –, Not detectable.