title: [Clinical pharmacokinetics].
abstract: The action of a drug depends on the quantity which reaches the site of its pharmacological action and how long it remains there. The necessary vital processes of the body dilute the active principle into different compartments of distribution, transform it into metabolites, and excrete it. Since a time duration of drug presence at the site of action is vital for the cure of disease, a comprehensive and quantitative expression of these time courses of drug distribution as a function of dose and route of administration is necessary for the establishment of proper dosage regimens for the treatment of disease and the avoidance of toxicities. The purpose of pharmacokinetics is to study these phenomena and to construct models suitable to explain them and to predict the behavior of drugs in conditions not yet studied. In this review some basic principles of pharmacokinetics (i.e. the compartment, the volume of distribution, the elimination half-life, etc.) are explained. Their clinical implications are shown in the case of multiple dose administration and in the study of the relations existing between blood levels of digoxin and the pharmacological action of this drug.
mesh_terms: D001835:Body Weight; D004077:Digoxin / Q000097:blood / Q000494:pharmacology*; D004334:Drug Administration Schedule; D007700:Kinetics; D010600:Pharmacology
chemical_list: D004077:Digoxin
vernacular_title: Pharmacocinétique clinique