A recently published guideline in the Schizophrenia Bulletin offers clear recommendations on using metformin to prevent weight gain associated with antipsychotic medications. Developed by researchers led by Aoife Carolan, Saint John of God Hospital and the Royal College of Surgeons, Ireland, the guidance aims to address a critical side effect of antipsychotic treatment.
Metformin, has shown promising results in reducing antipsychotic-induced weight gain. A Cochrane review revealed that it can reduce weight gain by an average of 4.03 kg compared with controls. The guideline recommends starting with 500 mg daily, increasing gradually to 1 g twice daily over six weeks.
Key Recommendations:
1. Start Metformin Proactively:
• With high-risk antipsychotics like olanzapine or clozapine.
• For medium-risk antipsychotics (e.g., quetiapine, risperidone) in patients with cardiometabolic risk factors, BMI 25–30, or ages 10–25 years.
2. Monitor Weight Changes: Initiate metformin if there’s a >3% increase in baseline weight within the first 12 months of treatment.
3. Consider Alternatives: For patients with BMI >30, GLP-1 agonists may be an option, though evidence for their preventive use is still limited.
Metformin should be discontinued if BMI drops below 20, antipsychotic therapy stops, or there are risks of lactic acidosis. It is contraindicated in patients with harmful alcohol use.
“At present, it is likely that metformin is underused and started only after significant weight gain. This guideline reflects a new practice for most clinicians,” Carolan, Royal College of Surgeons, Ireland.
Dr. Xiaoduo Fan from UMass Chan Medical School highlighted the growing interest in GLP-1 agonists. “Compared with metformin, GLP-1 agonists are more effective in inducing weight loss and mitigating cardiometabolic risks,” Fan said, though metformin remains a practical, cost-effective first-line option.
These guidelines represent a step forward in managing the metabolic side effects of antipsychotic therapy, enabling clinicians to take proactive measures for improved patient outcomes.
Journal Article : https://academic.oup.com/schizophreniabulletin/advance-article/doi/10.1093/schbul/sbae205/7919241
