Pharmacokinetics as an aid in the interpretation of toxicity tests.

A method is described which makes the detection of alterations in the pharmacokinetic profile possible when substances are administered during long-term toxicity tests. By superposition of a radioactive dose at the end of the toxicity study a blood level can be obtained which--on the assumption of first-order kinetics--is comparable to that after a single radioactive dose in controls. Differences between blood levels of pretreated and control animals may indicate enzyme induction or damage of the elimination organs, etc., even when morphological changes are evident.