Increasing relevance of pharmacogenetics of drug metabolism in clinical practice

Much of the individual variation in drug response is due to genetic drug me tabolic polymorphisms. Clinically relevant examples include acetylator stat us; cytochrome P450 2D6, 2C9 and 2C19 polymorphisms; and thiopurine methylt ransferase deficiency. It is important to be aware of which drugs are subje ct to pharmacogenetic variability. In the future, population-based pharmaco genetic testing will allow more individualized drug treatment and will avoi d the current empiricism.