Graphic methods in pharmacokinetics: the basics.

A considerable amount of information regarding the kinetics of drug absorption, distribution, metabolism, and excretion can be obtained by graphic analysis of plasma concentration and/or urinary excretion data. The simplest pharmacokinetic model is used to describe the analysis of drug concentration profiles in plasma after administration intravenous or nonvascular routes. Methods to calculate pharmacokinetic and pharmacologic parameters include urinary excretion rate, cumulative excretion, and the construction and analysis of Sigma-minus plots. The treatment for this simple pharmacokinetic model provides a basis for graphic analysis of more complex models.