Chlorphentermine may produce dual stimulus effects: a preliminary investigation.

1. Rats were trained to discriminate injections of either (+)-amphetamine (0.75 mg/kg) or (+/-)-fenfluramine (1.5 mg/kg) from saline in a two-lever drug discrimination task. 2. After stable discrimination performances were attained in each group, stimulus generalization studies were conducted with amphetamine, fenfluramine, and chlorphentermine. 3. Stimulus generalization (substitution) did not occur between amphetamine and fenfluramine when either drug was used as the training stimulus. 4. In contrast, both the amphetamine stimulus and the fenfluramine stimulus generalized completely to chlorphentermine. 5. Taken together, the results suggest that chlorphentermine may be capable of producing dual stimulus effects in animals.