Interspecies scaling of the pharmacokinetic parameters of coumarin among six different mammalian species.

The pharmacokinetic parameters, total body clearance, apparent volume of distribution and the terminal elimination half-life of coumarin were correlated among six mammalian species. It was demonstrated that the total body clearance was highly related to the liver blood flow, liver weight and body weight. The apparent volume of distribution appeared to be related only to body weight. The elimination half-life, which is dependent upon both the apparent volume of distribution and total body clearance, was poorly correlated with all physiologic variables that were evaluated. Hence, it appears that only the primary pharmacokinetic parameters of coumarin display a definite interspecies relationship.