EFFECTS OF REMOXIPRIDE, AN ATYPICAL ANTIPSYCHOTIC, ON COCAINE SELF-ADMINISTRATION IN THE RAT USING FIXED-RATIO AND PROGRESSIVE-RATIO SCHEDULES OF REINFORCEMENT

Remoxipride, a selective D2-dopamine receptor antagonist with preferen tial activity for mesolimbic-mediated behaviors, was assessed for its potential to block cocaine self-administration. The effects of remoxip ride (RMX) were evaluated using fixed-ratio-1 (FR-1) and progressive-r atio (PR) schedules of reinforcement. On FR-1, RMX pretreatment increa sed the rate of cocaine injections, while on a PR, breaking points wer e reduced. Daily RMX treatment also resulted in breaking point reducti ons, but the decreases in cocaine's reinforcing potency did not result in extinction of cocaine intake and were not sustained upon cessation of RMX. Thus, RMX can reduce the rewarding effects of cocaine, and if safely tolerated over sustained periods of treatment it, or drugs wit h a similar pharmacological profile, could provide a therapeutic adjun ct in the treatment of cocaine addiction.