Reinforcing and Discriminative Stimulus Effects of Ca-acetyl Homotaurine in Animals

Ca-acetyl homotaurine (Ca-AOTA) has been proposed as an adjunct for ethanol detoxification. The purpose of the present experiment was to determine whether Ca-AOTA would be predicted to have abuse potential. Rhesus monkeys that were experienced in the intravenous self-administration of cocaine (n = 2) or pentobarbital (n = 2) were given the opportunity to self-administer various doses of Ca-AOTA or its vehicle (0.9% saline). Ca-AOTA (1.0-10.0 mg/kg/injection, intravenously) was not self-administered above saline levels. The discriminative stimulus effects of Ca-AOTA were evaluated in a drug discrimination procedure in which animals were trained to make one response after a training drug and a different response after saline. Rhesus monkeys trained to discriminate d-amphetamine (n = 3) or pentobarbital (n = 3) from saline were tested with doses of Ca-AOTA ranging from 10 to 100 mg/kg (PO by nasogastric tube) and at 3 different pretreatment times (1, 2, or 4 hr). Ca-AOTA failed to engender drug-appropriate responding at any dose or pretreatment condition in either group of monkeys. In addition, Ca-AOTA was tested in 4 pigeons trained to discriminate pentobarbital from saline. Ca-AOTA administration did not result in pentobarbital-appropriate responding in doses ranging from 30-300 mg/kg (IM) and pretreatment times ranging from 30 to 240 min. The lack of both reinforcing properties and discriminative stimulus properties similar to d-amphetamine or pentobarbital suggests that Ca-AOTA has little or no abuse potential.