THE INTRAVENOUS SELF-ADMINISTRATION OF ANTIHISTAMINES BY RHESUS-MONKEYS

Rhesus monkeys were trained to lever press for infusions of cocaine during daily, 1-h experimental sessions. Following stabilization of the cocaine-maintained baselines, various antihistamines were substituted for cocaine to determine whether they would be self-administered. The results indicated that all monkeys tested self-administered tripelennamine and chlorpheniramine. One monkey out of the four self-administered pyrilamine, but only at a single (300-mu-g/kg) high dose. Phenyltoloxamine, cimetidine and hydroxyzine were not self-administered. These results further illuminate differences amongst H-1 antagonists in their potential for self-administration and, when examined in context with other reports, suggest that stimulant-like properties may help mediate their reinforcing effects when present.