Clinical potential of cariprazine in the treatment of acute mania.

Cariprazine (RGH-188, trans-4-{2-[4-(2,3-dichlorophenyl)-piperazine-1-yl]-ethyl}-N,N-dimethylcarbamoyl-cyclohexyl-amine hydrochloride), is a novel antipsychotic with dopamine D2 and D3 receptors antagonist-partial agonist properties. Cariprazine has also moderate affinity for serotonin 5-hydroxytryptophan (5-HT) 1A receptors, high affinity for 5-HT1B receptors with pure antagonism and low affinity for 5-HT2A receptors. Randomized, double blind, placebo controlled, flexible-dose (3-12 mg/day) studies have demonstrated cariprazine is effective in both schizophrenia and acute manic episodes associated with bipolar disorder. The incidence of serious adverse events in cariprazine arm was no different than in placebo arm in these studies. The most common adverse events were extrapyramidal symptoms, headache, akathisia, constipation, nausea, and dyspepsia which can be explained with cariprazine's partial dopamine agonism. Although cariprazine treatment was associated with a higher incidence of treatment-emergent adverse events, particularly akathisia and tremor, common side effects of marketed second generation antipsychotics such as weight gain, metabolic disturbances, prolactin increase or QTc prolongation were not associated with cariprazine, probably due to its moderate to low binding affinity for histamine H1 and 5-HT2C receptors. Animal studies show that cariprazine may have additional therapeutic benefit on impaired cognitive functioning with D3 receptor activity, however clinical data is still scarce. The aim of this article is to review the potential use of cariprazine for the treatment of acute manic episodes in the light of the preclinical and clinical trials reported to date.