A dopamine D2 receptor antagonist; selectively inhibits [3H]haloperidol and [3H]spiperone binding to dopamine D2 receptors over [3H]WB 4101, [3H]clonidine, and [3H]dihydroalprenolol binding to α1-adrenergic, α2-adrenergic, and β-adrenergic receptors, respectively, in rat striatal membranes (IC50s = 340, 66, >10,000, >10,000, and >10,000 nM, respectively); reduces apomorphine- and dopamine-induced decreases in gastrointestinal transit of charcoal dust in rat