Ro 15-4513 does not antagonize the discriminative stimulus- or rate-depressant effects of ethanol in rats.

Female rats, trained to discriminate between IP administered 1.2 g/kg ethanol (ETOH) and the saline vehicle (12 ml/kg), did not press the nondrug associated lever in tests with ETOH (0.9 and 1.2 g/kg) plus the purported amethystic imidazo benzodiazepine Ro 15-4513 (3 and 10 mg/kg) as examined at two intervals after ETOH administrations viz. 7.5 and 15 min. The two doses of Ro 15-4513 were administered 5 min prior to ETOH. Response times were increased in tests with the combination. ETOH in expired air was not different in the two drug conditions, i.e., ETOH singly and together with Ro 15-4513, irrespective of the dose combinations examined. Rats trained to press a bar (FR-10 operant behavior) for sweetened water disclosed increases in the time used to obtain the reinforcer after treatments with ETOH and Ro 15-4513. Thus, Ro 15-4513 did not seem to reverse any of the behaviors examined in this study.