Chapter 6 - Drug Discrimination: Use in Preclinical Assessment of Abuse Liability

Abstract

The drug discrimination procedure relies on psychoactive effects of drugs, which is a prerequisite for abuse. Novel drugs should be tested in drug discrimination studies using relevant reference compounds as training drugs and in some cases the drug under investigation should be used as a training drug against which reference compounds are tested. The drug discrimination procedure is particularly well-suited for assessing the duration of a psychoactive effect and caution is advised against relying on pharmacokinetics only to determine onset and offset of pharmacological effects since these often do not match. Drug discrimination is particularly useful as the first line behavioral abuse liability model, first by relying on a two-choice design, thereby conferring resistance to confounding effects which may nonselectively suppress responding in one-choice models, and second by allowing drugs to be administered by any route. Therefore, drug discrimination data are very useful for dose range finding for further abuse liability assessment.