A non-selective 5-HT receptor antagonist; potent antagonist of 5-HT1A and 5-HT1B (IC50 = 16 nM and Ki = 0.2 nM, respectively); potent antagonist of 5-HT2A, 5-HT2B, and 5-HT2C receptors (Kis = 3.16, 2.08, and 4.46 nM, respectively); binds to 5-HT5A, 5-HT5B, 5-HT6, and 5-HT7 receptors (Kds = 100, 15.8, 1.8, and 1 nM, respectively); has been used to characterize the role of serotonin in various biological processes