Alterations in amino acid levels in mouse brain regions after adjunctive treatment of brexpiprazole with fluoxetine: comparison with (R)-ketamine
Brexpiprazole is a dopamine D₂receptor partial agonist. Compared with aripiprazole, it is more potent at 5-HT1A receptors and displays less intrinsic activity at D₂receptors. Brexpiprazole also has potent antagonistic activity at 5-HT2A as well as alpha-adrenergic receptors. In addition to results from phase II trials, data are available from two pivotal phase III, randomized, placebo-controlled trials of brexpiprazole for the acute treatment of schizophrenia and two pivotal phase III, randomized, placebo-controlled trials of adjunctive brexpiprazole for the acute treatment of major depressive disorder in patients with inadequate response to antidepressant medication treatment. Overall tolerability is promising, with rates of discontinuation due to adverse events lower or slightly higher than that observed for placebo. Although overall akathisia was more commonly observed with brexpiprazole than with placebo, the absolute risk increase attributable to brexpiprazole appears small. Short-term weight gain appears modest; however, outliers with an increase of ≥ 7% of body weight were evident in open-label long-term safety studies.