All the patients were genotyped and grouped according to predicted phenotype for CYP2D6 and CYP2C19. Information about medication use was collected. Patients using CYP2D6 or CYP2C19 inhibiting medication according to Flockhart were selected. Enzyme activity scores of patients using a strong inhibitor were multiplied by 0 which meant they converted automatically to a PM phenotype. In patients using medium inhibitors, activity scores were multiplied by 0.5. This is a widely used and accepted method.