[Effectivity of drugs in the elderly with regard to their pharmacokinetics and pharmacodynamics (author's transl)].

In principle, in all periods of life drugs act with the same mechanisms. Characteristics modifications of drug effects are caused by age dependent special constellations of pathogenesis and course of the illness, as well as of the multimorbidity in relation to physiological ageing. The most important functional process of ageing is the progressively decreasing adaptability towards environmental conditions with interindividually distinct deviations. If elderly patients react quantitatively in an unexpected fashion, the reason can be a different absorption, distribution, renal or metabolic elimination of the drug. But there exists also an age dependent sensitivity towards drugs, which can be explained in a modified reaction-pattern of the receptors.