An agonist of the Gαi-linked dopamine receptors D2, D3, and D4 (Ki = 3.9, 2.2, 0.5, and 5.1 nM for D2S, D2L, D3, and D4, respectively); relatively inactive at the Gαs-linked dopamine receptors D1 and D5, as well as at serotonin and adrenergic receptors