| Medication | Gene |
| Ondansetron, Tropisetron | CYP2D6 |
| Rabeprazole, Pantoprazole, Esomeprazole, Lansoprazole, Omeprazole, Dexlansoprazole | CYP2C19 |
Frequency of Cytochrome P450 (CYP2D6, CYP2C19) Metabolizer Types in the population
| Cytochrome | Poor metabolizer | Intermediate metabolizer | Normal metabolizer | Rapid or ultra-rapid metabolizer |
| CYP2D6 | 4-7% | 9-35% | 50-90% | 2-3% |
| CYP2C19 | 2-20% | 24-36% | 14-44% | 30% |