A phenothiazine classified as an antipsychotic compound; antagonizes dopamine and serotonin receptors (Kis = 0.66, 0.84, 1.2, and 1.8 nM for D2, D3, D4, and 5-HT2A, respectively); also antagonizes histamine, α1- and α2-adrenergic, and muscarinic acetylcholine receptors.