Pharmacogenetics, Ethnic Differences in Drug Response and Drug Regulation

Introduction V ariation in drug response between individuals arises from differences in the

dose-concentration (pharmacokinetic) and/or the concentration-response (pharmacodynamic) relationships of a drug. Either of these two relationships can be modulated by a number of genetic and nongenetic factors. Depending on the drug, genetic factors have been suggested to account for 20 to 95 % of the variability in drug disposition and clinical effects.1,2 This varia­ tion extends not only between individuals but also between ethnic groups.