No pain relief from codeine ...? An introduction to pharmacogenomics

Drug treatment remains a mainstay of medicine. In some situations a drug un expectedly has no effect, or unforeseen serious side effects occur. For the patient this represents a dangerous and potentially life-threatening situa tion. It certainly is a distressing experience for the doctor. At the socie tal level, adverse drug reactions represent a leading cause of disease and death. Genetic variation often underlies these unexpected situations. Pharm acogenetics is the term used about genetically determined variability in th e metabolism of drugs. Pharmacogenomics usually refers to drug discovery ba sed on knowledge of genes, but it is a discipline that offers insight into aetiologic mechanisms, and possible prevention and treatment. There is a tr end towards a definition of pharmacogenomics that includes both pharmacogen etics and pharmacogenomics as defined above. Our article is an introduction to pharmacogenomics, using the broader definition. Biotechnological method s cannot be understood without a grasp of basic medical genetics, and we pr ovide a brush-up on the fundamentals. We then outline pharmacogenetics, giv ing examples of genetically based variation in drug metabolising enzymes, d rug receptors and drug transporting proteins. Modem biotechnology would be unthinkable without the aid of computers, and we briefly touch upon the fie ld of bioinformatics. Finally, we give an overview of pharmacogenomics in t he narrower sense. The rapidly growing field of pharmacogenomics is going t o influence our everyday practice of medicine in the immediate future.