L-745870 hydrochloride is a potent, selective, brain-penetrant and orally active dopamine D4 receptor antagonist with a Ki of 0.43 nM. L-745870 hydrochloride shows weaker affinity for D2 (Ki of 960 nM) and D3 (Ki of 2300 nM) receptors, and exhibits moderate affinity for 5-HT2 receptors, sigma sites and α-adrenoceptors.