[Customized drug therapy--how near is the goal?]

During the last years we have gained considerable knowledge , about genetic factors behind the huge inter-individual variation in drug response and the risk of adverse drug reactions.

The article is based upon a recent search in PubMed and the author's own studies and experience with genotyping related to drug therapy.

A considerable genetic variability has been revealed both in the function of drug-metabolising enzymes, transport proteins participating in drug distribution and excretion, and drug targets. This variability may be important for the choice and dosage of a drug. A number of genotyping methods are available for routine pharmacogenetic testing today. In some cases, genotyping is helpful before start of drug therapy, while in other cases genotyping is not indicated before a clinical problem has arisen and needs treatment. Although there are some clear-cut examples of genotyping being important for customising drug treatment, the next decades will determine whether genotyping will make it possible to predict treatment response as a general principle before starting drug therapy.