Rexulti (brexpiprazole) is an atypical antipsychotic medication approved by the FDA for three conditions: as an add-on treatment for major depressive disorder in adults, for schizophrenia in adults and teens aged 13 and older, and for agitation associated with Alzheimer’s disease. It’s taken as a once-daily tablet, with dosing that varies depending on the condition being treated.
Add-On Treatment for Depression
Rexulti’s most common use is as an adjunctive (add-on) therapy for major depressive disorder. It’s not prescribed on its own for depression. Instead, it’s added to an existing antidepressant when that antidepressant alone isn’t providing enough relief. This combination approach targets patients who’ve had an inadequate response to one or more antidepressants, a situation that affects a significant portion of people with depression.
For this use, the starting dose is typically 0.5 mg or 1 mg once daily, gradually increased each week to a target of 2 mg daily. The maximum dose is 3 mg. You can take it with or without food. The clinical trials that established its effectiveness for depression ran for six weeks, so it may take several weeks before the full benefit becomes apparent.
Treatment of Schizophrenia
Rexulti is also approved as a standalone treatment for schizophrenia. Adults start at 1 mg daily for the first four days, then increase to 2 mg, and potentially up to 4 mg based on response. Teens aged 13 to 17 follow a slower schedule, starting at 0.5 mg and working up to a target range of 2 to 4 mg daily with weekly increases of 1 mg at a time. The maximum dose for both groups is 4 mg per day.
Agitation in Alzheimer’s Disease
In 2023, Rexulti became one of the first medications specifically approved for treating agitation associated with Alzheimer’s dementia. This is a notable distinction because agitation, including pacing, verbal aggression, and physical restlessness, is one of the most distressing behavioral symptoms for both patients and caregivers, yet few drugs have been formally approved for it.
In a randomized clinical trial published in JAMA Neurology, patients receiving 2 to 3 mg daily showed a statistically significant reduction in agitation scores compared to placebo after 12 weeks. One important limitation: Rexulti is approved only for ongoing daily use in this population, not as an as-needed medication for sudden episodes of agitation.
How Rexulti Works
Rexulti belongs to the same drug class as aripiprazole (Abilify), but it was designed to be a refined version. Both medications act on dopamine and serotonin receptors in the brain, but Rexulti was intentionally engineered to be less activating. It has weaker stimulating activity at dopamine D2 receptors than aripiprazole, which makes it function more as a blocker at those receptors. It also binds more potently to certain serotonin receptors and a type of adrenaline receptor.
The practical result of this pharmacological profile is that Rexulti tends to produce fewer activation-related side effects, like the restlessness and insomnia that some people experience with aripiprazole. This “dialed down” design was a deliberate choice to improve tolerability while maintaining therapeutic effects across its three approved uses.
Common Side Effects
The side effects that showed up most frequently in clinical trials overlap across all three approved uses. For depression (when added to an antidepressant), the most common effects occurring at notably higher rates than placebo were weight gain, drowsiness, and akathisia, a type of inner restlessness that makes it difficult to sit still. For schizophrenia in adults, weight gain, akathisia, headache, drowsiness, and insomnia each occurred in at least 5% of patients. Teens with schizophrenia experienced a similar profile, with the addition of upper respiratory symptoms.
Weight gain deserves particular attention because it’s the most consistently reported side effect across every approved indication and every age group studied. If you’re starting Rexulti, tracking your weight regularly gives you and your prescriber useful data for evaluating whether the benefits outweigh this risk.
Important Safety Warnings
Rexulti carries two FDA boxed warnings, the most serious type of safety alert. First, antipsychotic medications as a class increase the risk of death in elderly patients with dementia-related psychosis. While Rexulti is approved for agitation in Alzheimer’s disease specifically, it is not approved for treating psychosis related to dementia more broadly. These are distinct clinical situations. Second, antidepressants (and by extension, medications used alongside them) have been associated with increased suicidal thoughts and behaviors in children and young adults. Close monitoring is especially important during the first few months of treatment or after dose changes.