OVERVIEWThe word pharmacokinetics was coined from the Greek work Pharmakon means drugs and poisons. Wargner in 1968 and 1975 defined pharmacokinetics as the evolution over time of the concentrations or quantities of drugs and metabolites in biological fluids, tissues and excreta, and also of the pharmacological response, and to construct suitable models for interpret these data. In pharmacokinetics, data is analyzed using a mathematical representation of part or all of an organism. Gilbaldi and Levy in 1976 gave a related definition, they defined pharmacokinetics as the study of a characterization of the time course of the absorption, distribution, metabolism and metabolism of a drug. excretion, and with the relationship of these processes with the intensity and evolution over time of therapeutic and adverse effects of drugs. ORIGINS OF THE SUBJECT The first attempt at what led to pharmacokinetics/pharmacodynamics was first described by Buchanan Andrew in his work “Physiological Effects of Ether Inhalation”. Buchanan pointed out that for short inhalations of ether, the speed of recovery was related to the redistribution of ether in the body and went further by calculating the amount of ether inhaled, exhaled and retained during induction with this short-acting anesthetic (Buchanan 1847, Butler, 1964). ).In 1913, the Michaelis-Menten equation used to describe enzyme kinetics was published by Michaelis and Menten and the equation was used to describe drug elimination kinetics (Michaelis and Menten 1913). Another wonderful work on the origin of the subject is from Swedish investigators. In 1924, Windmark and Tandberg published equations now known as the (a) one-compartment open model with intravenous bolus injection and multiple doses administered at uniform intervals... ... middle of paper ..... . Schaldemose, 1959). Another great contribution to pharmacokinetics during this period is (a) the introduction of the curve fitting method based on polyexponential equations (Perl, 1960); and (b) the introduction of the use of an analog computer to adjust and simulate pharmacokinetic data and in model building (Garrett et al, 1960; Wiegand and Taylor, 1960). The first symposium whose title incorporated the term pharmacokinetics was held in Bors. - tel, Germany in 1962. The proceedings of this symposium were powerful forces spreading the idea of ​​pharmacokinetics. Experimental verification of papers by Wagner 1976 which suggest that if a panel of subjects received the same dose of drug by the same route of administration and blood concentration time data were fitted by polyexponential equations with the statistically optimal number terms per dataset