CP-809101 hydrochloride is a potent and highly selective 5-HT 2C receptor agonist, with pEC 50 s of 9.96, 7.19 and 6.81 M for human 5HT 2C , 5HT 2B and 5HT 2A receptor. CP-809101 hydrochloride inhibits conditioned avoidance responding in rats and antagonizes both PCP (phencyclidine hydrochloride)- and d-amphetamine-induced hyperactivity. CP-809101 hydrochloride also reduces food and nicotine dependence in rats, can be used in studies of antipsychotic and nicotine dependence .