Sannerud C A, Griffiths R R
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Drug Alcohol Depend. 1988 Jul;21(3):195-202. doi: 10.1016/0376-8716(88)90070-1.
The ability of amantadine to maintain self-injection behavior and to alter self-administration of cocaine was examined in baboons using a standard intravenous cocaine self-injection procedure. Responding was maintained under a FR 80- or 160-response schedule of intravenous cocaine delivery (0.32 mg/kg per injection). Each drug injection was followed by a 3-h time-out allowing a maximum of 8 injections/day. Vehicle or amantadine doses were substituted for cocaine for a period of 15 or more days. Evaluation of a wide range of amantadine doses (0.32-32 mg/kg per injection) showed that this compound did not maintain self-administration behavior above vehicle control levels. In another experiment using the cocaine self-injection baseline, amantadine (10 or 32 mg/kg per day) was administered via a chronic intravenous infusion. Cocaine self-injection behavior was maintained and re-initiated during chronic amantadine exposure, suggesting that the reinforcing efficacy of cocaine was not modified by chronic amantadine administration.