In clinical practice the individual response to a drug represents a great problem. Many of us experienced a situation when the drugeffect declined or drug-related toxic reaction occurred.
The typical example is the variation of optimal warfarin dosage. The main causeof interindividual differences in the drug response is the polymorphism in drug resorption and elimination systems, enzymesresponsible for drug biotransformation, target receptors or signal molecules.
The individualized drug therapy requires physicians to beoriented in main causes of pharmacokinetic and pharmacodynamic variations and be able to predict accurately the individual drug response