Medications for weight gain

How is weight gain relevant for people with schizophrenia? 

Many antipsychotic medications are associated with weight gain, and various pharmacological approaches have been investigated for this problem. Effective adjunctive pharmaceutical treatments for side effects such as weight gain increase adherence to antipsychotic medications and reduces the risk of psychotic relapse.

What is the evidence for adjunctive medications for weight reduction?

Moderate quality evidence finds a benefit of adjunctive metformin for reducing weight in adults and children with schizophrenia. Moderate to low quality evidence finds more weight reduction with metformin plus lifestyle intervention than placebo (less 5.05kg), metaformin alone (less 1.5kg) or lifestyle intervention alone (less 3.30kg). Triglycerides, glucose, insulin and cholesterol levels may also be improved with metformin.

There were large effects of reduced weight and BMI with topiramate. There were also medium to large effects of improved triglycerides and low-density lipoproteins with topiramate. Lower quality evidence finds improvements with topiramate in fasting blood insulin, insulin resistance and systolic blood pressure. There were no improvements over placebo in total cholesterol, high density lipoproteins, leptin, fasting blood glucose and diastolic blood pressure.

Moderate quality evidence finds more weight reduction with adjunctive reboxetine or sibutramine than placebo. Glucagon-like peptide-1 receptor agonists also reduce weight, waist circumference and BMI, and improve haemoglobin A1c, glucose and visceral adiposity. Moderate to low quality evidence also finds benefits of adjunctive amantadine for weight reduction. Moderate to low quality evidence finds reduced BMI, but not weight with adjunctive ranitidine.

Moderate quality evidence suggests switching antipsychotic medications from olanzapine to aripiprazole or quetiapine may reduce weight and blood glucose levels.

There were no benefits for weight of adjunctive fluoxetine, rosiglitazone famotidine, nizatidine, norepinephrine, orlistat, or metformin + sibutramine, and no benefits for metabolic disturbances of adjunctive melatonin.

October 2020

Image: ©terovesalainen –

Last updated at: 3:58 am, 31st August 2021
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Fact Sheet Technical Commentary
Tags:  Weight gain

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