Why does Rexulti cause weight gain?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on Jan 17, 2025.

Official Answer by Drugs.com

Key Points

Although effects can vary between patients, medicines in the atypical antipsychotic class like Rexulti are often associated with weight gain, possibly due to an increased appetite, less physical activity because of side effects like drowsiness or fatigue, and changes in metabolism.

Rexulti (brexpiprazole) is an atypical antipsychotic used to treat patients with major depressive disorder (MDD), schizophrenia, and agitation associated with dementia due to Alzheimer’s disease. Weight gain is one of the most commonly reported side effects of Rexulti in patients treated for either depression or schizophrenia.

You and your healthcare provider should check your weight on a regular basis while taking this medicine.

Depression studies

In two 6-week long studies of adults with depression, 2% to 5% of patients taking Rexulti plus an antidepressant reported at least a 7% increase in body weight, compared with 2% of patients taking an antidepressant plus a placebo (a pill that contains no medicine).

In studies of patients treated for depression with Rexulti, 4% of patients discontinued the treatment due to a weight increase. At the end of a one-year study, patients had gained an average of 3.1 kg (6.8 lb) from the start of the study. Results showed 30% of patients had a 7% or greater increase in body weight, while 4% had a 7% or greater decrease in body weight.

Schizophrenia studies

In studies of patients treated for schizophrenia, 0.6% of patients discontinued Rexulti treatment due to a weight increase. Results showed 20% of patients had a 7% or greater increase in body weight, while 10% had a 7% or greater decrease in body weight. At the end of a one-year study, patients taking Rexulti had gained an average of 2 kg (4.4 lb) from the start of the study.

In pediatric studies, 0.5% of patients 13 to 17 years of age discontinued due to weight increase. The mean increase in weight was 3.8 kg (8.4 lb). Z scores, which adjust for normal growth in a child, showed that 20% of children had an increase in age-and-gender-adjusted body weight z-score of at least 0.5 SD from baseline, a clinically significant effect.

Rexulti may lead to other metabolic side effects that are also linked with antipsychotic treatments, such as high blood sugar, type 2 diabetes, and increased lipids levels like cholesterol and triglycerides. Your doctor will monitor you for these changes.

Agitation associated with dementia due to Alzheimer’s studies

In patients with agitation associated with dementia due to Alzheimer’s disease, 2% of patients had at least a 7% increase in body weight at any visit compared to 0% in those taking a placebo (a pill with no medicine).

In a 12-week long extension study after the initial 12 week treatment period, there was no mean change in weight at their last study visit. Overall, 4% of patients demonstrated at least a 7% increase in body weight, and 5% showed at least a 7% decrease in body weight from baseline to last visit.

Bottom Line

Rexulti (brexpiprazole) is in a class of medicines known as atypical antipsychotics. Although your results may vary, the atypical antipsychotic class is often associated with weight gain, possibly due to changes in metabolism, an increased appetite and less physical activity because of side effects like drowsiness or fatigue.

Weight gain is one of the most commonly reported side effects of Rexulti in patients treated for either depression or schizophrenia, but not everyone gains weight. For example, at the end of a one-year study in adults being treated with Rexulti for depression (in addition to an antidepressant), patients had gained an average of 3.1 kg (6.8 lb) from the start of the study. Results showed 30% of patients had a 7% or greater increase in body weight, while 4% had a 7% or greater decrease in body weight.

This is not all the information you need to know about Rexulti (brexpiprazole) for safe and effective use. Review the full Rexulti information here, and discuss this information and any questions you have with your doctor or other health care provider.

References

Rexulti (brexpiprazole) [product information]. Otsuka Pharmaceutical Co. Rockville, MD. 5/2024. Accessed Jan 17, 2025 at https://www.otsuka-us.com/sites/g/files/qhldwo10016/files/media/static/Rexulti-PI.pdf
Rexulti.com. Efficacy data for Rexulti. Accessed Jan 17, 2025 at https://www.rexultihcp.com/sz/safety#adverse-reactions
Rexulti.com. Why Rexulti. Accessed Jan 17, 2025 at https://www.rexulti.com/mdd/why-rexulti

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Why does Rexulti cause weight gain?

Key Points

Depression studies

Schizophrenia studies

Related questions

Agitation associated with dementia due to Alzheimer’s studies

Bottom Line

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