Benzodiazepine modulation of opiate reward

Case studies reveal that opiate addicts often premedicate themselves with benzodiazepine (BDZ) tranquilizers prior to taking their opiate. It has been hypothesized that such actions occur because the BDZ enhances the euphoric or reinforcing properties of the opiate. The present study tested this hypothesis in the animal laboratory. Sprague-Dawley rats were used to examine whether the magnitude of conditioned preferences for a distinctive environment associated with intravenous heroin delivery would be augmented by intraperitoneal alprazolam pretreatment. Results demonstrated that alprazolam produced a leftward shift of the heroin dose-response curve in the conditioned place preference test. The data obtained are consistent with the view that BDZs can augment the affective response to heroin in laboratory animals.