Blonanserin is a 4-phenyl-2-(1-piperazinyl) pyridine that acts as an antagonist at dopamine D2, D3, and serotonin 5-HT2A receptors (Kis = 0.14, 0.49, and 0.81 nM, respectively). It binds to 5-HT6 with a Ki value of 11.7 nM and demonstrates relatively low affinity for 5-HT2C (Ki = 26.4 nM), adrenergic α1 (Ki = 26.7 nM), histamine H1 (Ki = 765 nM), and muscarinic M1 receptors (Ki = 100 nM). Blonanserin was developed in Japan as a novel antipsychotic that displays 20- and 94-fold higher affinity for D2 receptors compared to haloperidol and risperidone , respectively.