The problem of pharmacogenetics in pathology

In medical practice, the individual characteristics of the response to the introduction of the same doses of the drug are often noted. In old manuals one can find references to "medicinal idiosyncrasies" as extreme degrees of deviation of individual reactions, but without any explanation of the mechanisms. Attempts have been made to explain unusual drug reactions in terms of allergy [4, 8]. However, only the advances in genetics made it possible to reveal the individual characteristics of the response to various pharmacological drugs. The starting point for solving the problem was the research that showed that the concept of the "norm" of enzyme activity in various fluids and tissues of the body is very conditional and that there is a wide range of fluctuations in the activity of enzymes in different individuals. This phenomenon is determined by the genetic heterogeneity of the enzyme-producing cells. It turned out that even in monozygous twins, the enzyme activity is different; this gave grounds to speak about the biochemical individuality of the organism [13].