What is Required from Toxicokinetic Studies?—The Viewpoint of Japanese Kineticists

Abstract

A questionnaire study on the general opinions toward toxicokinetics in Japan revealed that: most Japanese companies currently perform toxicokinetic studies only when they feel them to be warranted. Most believe, however, that in the future, toxicokinetic studies should be integrated into toxicology studies. In order to support and to make toxicokinetics more effective, basic pharmacokinetic studies are necessary at the earliest stage of drug development. Another questionnaire study revealed that most Japanese companies consider the radiolabeled repeat dose pharmacokinetic studies to be informative and useful. These studies, however, should not be uniformly required for all drugs. Rather, they should only be required under certain conditions. Application of a sensitive new radioisotope technology, radioluminography, was outlined and its usefulness in basic animal pharmacokinetic and metabolic studies was pointed out.