Brexpiprazole: a new leaf on the partial dopamine agonist branch

Brexpiprazole is a new dopamine partial agonist antipsychotic in the same class as aripiprazole. This paper will briefly review brexpiprazole and compare it with aripiprazole. Brexpiprazole and aripiprazole are both partial agonists at dopamine D2, and serotonin 5-HT1A and antagonists at serotonin 5-HT2A and noradrenergic α1B receptors. However, the two drugs are significantly different in potencies at various receptors; neurochemical profiles predict that brexpiprazole may be comparable with aripiprazole in its antipsychotic efficacy but may cause less akathisia, extrapyramidal side effects (EPS) and activation. In pivotal trials brexpiprazole demonstrated antipsychotic efficacy in short and long-term studies; it was also found to be an effective adjunct in patients with major depression resistant to antidepressants. Akathisia can occur early in treatment with brexpiprazole, as can minor weight gain and prolactin elevation. Indirect data extrapolations from pivotal studies suggest that brexpiprazole and aripiprazole have comparable efficacy but brexpiprazole may cause less akathisia. Like aripiprazole, brexpiprazole has been approved in the USA for use in schizophrenia and antidepressant-resistant depression. Although much more clinical experience is needed, brexpiprazole appears to be distinct from aripiprazole and a promising new ‘metabolically-friendly’ antipsychotic option for treatment of psychoses and mood disorders