Dopamine D3 receptor antagonist; 133-fold selective for D3 over D2 receptors in vitro (Ki values are 0.70, 93.3 and 375 nM for D3, D2 and D4 receptors respectively). Attenuates abnormal involuntary movements associated with L-DOPA (Cat. No. 3788) in rat models of Parkinson's disease. Inhibits the effects of methamphetamine; attenuates drug-induced behaviors in vivo.