Brexpiprazole (Rexulti)

Class

Second-generation (atypical) antipsychotic

Mechanism

Partial agonist at dopamine D2 and serotonin 5-HT1A receptors; antagonist at serotonin 5-HT2A and 5-HT2B receptors; may enhance prefrontal glutamatergic transmission via a dopamine D1 receptor-dependent mechanism

FDA-Approved Use

Schizophrenia, adjunctive treatment of major depressive disorder (MDD), agitation associated with dementia due to Alzheimer’s disease (AD)

Off-Label Use

Behavioral disturbances in traumatic brain injury (TBI), irritability and aggression in intellectual disability

Formulation

Oral tablets (0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg)

Titration

0.5–1 mg p.o. daily; titrate every 1–2 weeks as tolerated

Dose Range

0.5–3 mg/day (for MDD adjunct or agitation in dementia); up to 4 mg/day for schizophrenia

Kinetics

Half-life ~91 hours; metabolized via CYP3A4 and CYP2D6; steady state reached in ~10–12 day

Common AEs

Weight gain, akathisia, somnolence, fatigue, agitation

Serious/Rare AEs

Extrapyramidal symptoms (EPS), impulse control disorders, neuroleptic malignant syndrome (NMS), orthostatic hypotension

Monitoring

Monitor weight, fasting glucose, lipids, and EPS every 3–6 months; consider behavioral monitoring for impulse dysregulation

Black Box Warning

Increased risk of mortality in elderly patients with dementia-related psychosis; increased risk of suicidal thoughts and behaviors in children, adolescents, and young adults with MDD

Considerations

Brexpiprazole may be preferred in patients at risk for metabolic complications due to its relatively favorable weight and metabolic profile compared to other antipsychotics. While FDA-approved for agitation in Alzheimer’s disease (AD), it still carries the class-wide warning for increased mortality in elderly patients with dementia-related psychosis and should be used cautiously. Preliminary evidence suggests it may reduce behavioral disturbances in patients with traumatic brain injury (TBI) or intellectual disability, though data remain limited. Clinicians should monitor for activation symptoms, including akathisia or agitation, and assess for impulse control problems, particularly in patients with a prior history of behavioral dysregulation.