A potent and selective antagonist of the serotonin receptor 5-HT2A (Ki = 0.36-0.85 nM); weakly binds 5-HT2C, α1-adrenergic, and sigma receptors (Ki = 88, 128, and 87 nM) and much less effectively associates with other serotonin, dopamine, adrenergic, muscarinic acetylcholine receptors and monoamine transporters