RESUMEN
Personalized medicine - a new direction in medicine, which is based on the study of various biomarkers and the use of new methods of molecular analysis (primarily evaluating the activity of isoenzymes of cytochrome P450), allowing individualized approach to the selection of both the drugs and the selection of the dosing regimen for the purpose of maximize the effectiveness and safety of pharmacotherapy. This personalized medicine is to change the development and use of preventive and curative interventions. Genetic polymorphism isozymes of cytochrome P450 may determine the individual activity of a particular isozyme, and thus, to predict the clinical effectiveness, and in some cases, the risk of adverse reactions. The article is an example of the use of information on the activity of cytochrome P450 in clinical practice in matters of diagnosis, treatment and prevention of diseases. The scheme of the five best-known activity of isoenzymes of cytochrome P450 is shown.