5-HT2A receptor antagonist that also displays high affinity at D4 receptors (Ki values are 0.26, 2.93, 25, 38, 70 and 726 nM for 5-HT2A, D4, H1, α1, 5-HT1A and D2 receptors respectively). Inhibits inositol phosphate formation evoked by 5-HT in vitro (IC50 = 7.76 nM) and antagonizes mescaline-induced head twitches in vivo.