Cariprazine hydrochloride (RGH188 hydrochloride) is an antipsychotic drug, is a D3 and D2 receptor partial agonist((Ki of 0.085 nM and 0.49 nM, respectively)

D3 receptor:0.085 nM (Ki) , D2 receptor:0.49 nM (Ki) , 5-HT1A receptor:2.6 nM (Ki)

Cariprazine occupied D(2)/D(3) receptors in a dose-dependent and saturable manner, with the lowest dose occupying ~5% of receptors and the highest dose showing more than 90% occupancy. 5-HT(1A) receptor occupancy was considerably lower compared with D(2)/D(3) occupancy at the same doses, with a maximal value of ~30% for the raphe nuclei[1].

Three monkeys using the following PET radioligands: [(11)C]MNPA (an agonist at D(2) and D(3) receptors), [(11)C]raclopride (an antagonist at D(2) and D(3) receptors), and [(11)C]WAY-100635 (an antagonist at 5-HT(1A) receptors). During each experimental day, the first PET measurement was a baseline study, the second after a low dose of cariprazine, and the third after the administration of a high dose[1].