Translation of pharmacokinetics to clinical medicine

The translation of pharmacokinetics to clinical medicine involves answering the following question: “When the pharmacodynamic or chemotherapeutic activity of a drug is known, how must its dosage regimen be adapted to its pharmacokinetic characteristics so that the desired therapeutic effect may be achieved and maintained?” This presentation discusses examples of pharmacokinetic analyses which influence the practice or principles of practical therapeutics. Physicians have intuitively appreciated the basic importance of pharmacodynamics because they are primarily interested in the action of a drug on the patient. However, in pharmacokinetics we consider the fact that there is not only a unidirectional action but also a mutual interaction between drug and organism. The action of the organism on the drug may be summarized in terms of the pharmacokinetic parameters: absorption, distribution, metabolism, and excretion. These parameters are examined with respect to drug accumulation, relation of pharmacokinetic data to therapeutic effects, saturation phenomena, the effect of kidney disease, the variation of pharmacokinetic parameters in individual patients due to age, pH of body fluids, and the states of wakefulness.