Effects of the Atypical Antipsychotics Amperozide and Clozapine on Behavior Maintained by Food, Cocaine, or Alfentanil in Rhesus Monkeys

Amperozide and clozapine are antipsychotic drugs that act primarily as antagonists at 5-hydroxytryptamine (5HT₂) sites. In different groups of rhesus monkeys (Macaca mulatta) receiving food, cocaine, or alfentanil as a consequence of responding on FR 30 schedules, the antipsychotic drugs produced dose-dependent decreases in behavior. Amperozide was more potent in suppressing food or cocaine-maintained responding than in suppressing alfentanil-maintained responding. Clozapine was nearly equally potent in suppressing behavior maintained by the different reinforcers. Neither drug showed a specificity of effect that suggests use in the treatment of cocaine or opioid abuse.