Drug discrimination and drug stimulus generalization with anxiolytics

Work with lorazepam in two‐lever food‐maintained drug discrimination procedures with baboons and rats found greater specificity in the generalization profile when this drug was used as a training drug compared to studies with other benzodiazepines (BZ). That is, animals trained to discriminate lorazepam have not reliably made the drug response in tests with barbiturates, although animals trained to discriminate diazepam, chlordiazepoxide, triazolam, oxazepam, and sometimes midazolam commonly have done so. Characterization of the discriminative stimulus effects of lorazepam has included manipulation of species, training dose, and route of administration; drug interaction studies; and tests with a variety of anxiolytics. The time course of the discriminative stimulus effects of lorazepam and other drugs also has been studied using a multiple session procedure in baboons. Some of these results have provided information relevant to the extent to which intermediate levels of the drug response in test sessions at doses that do not reduce response rates may meaningfully reflect threshold or partial drug stimulus effects.