Potent and selective dopamine D3 receptor antagonist (Ki values are 1.4, 217, 223, 642, > 5000, > 10000 and > 10000 nM for D3, D2, 5-HT2, α1, D4, D1 and D5 receptors respectively). Potently antagonizes quinpirole-stimulated mitogenesis (IC50 = 6.8 nM). Attenuates cocaine's rewarding effects and inhibits relapse to drug-seeking behavior.