An examination of the intravenous self-administration of phenylpropanolamine using a cocaine substitution procedure in the baboon

Intravenous self-administration of phenylpropanolamine HCl (0.10 to 10.0 mg/kg/injection) was examined in baboons under conditions in which baseline responding was maintained by intravenous injections of cocaine HCl (0.32 mg/kg/injection). Drug was available under a FR 160-response schedule of intravenous injection. Each drug injection was followed by a 3-hr time-out allowing a maximum of eight injections per day. Phenylpropanolamine or phenylpropanolamine vehicle (saline) was substituted for cocaine for a period of 15 days followed by a return to the cocaine baseline. Response rates after phenylpropanolamine substitution were similar to those maintained by saline substitution, and lower than those maintained under cocaine baseline conditions. At the two highest doses of phenylpropanolamine tested (3.2 and 10.0 mg/kg/injection) concurrent food maintained behavior was suppressed.