A newly published guideline, issued in the Schizophrenia Bulletin on December 9, offers expert recommendations for the use of metformin to prevent weight gain caused by antipsychotic medications. This guideline, developed by Aoife Carolan and colleagues from Saint John of God Hospital in Dublin, provides evidence-based strategies for managing one of the most common side effects of antipsychotic drugs—weight gain, which can lead to other significant health complications.
Antipsychotic-induced weight gain (AIWG) is a widespread issue, often leading to increased risks for obesity, diabetes, and cardiovascular problems. According to the guideline, metformin, a medication primarily used for managing type 2 diabetes, is the only pharmacological treatment shown to effectively prevent AIWG. Studies have shown that the co-administration of metformin with antipsychotics can reduce weight gain by an average of 4.03 kg compared to controls.
The guideline emphasizes the importance of timely intervention, recommending the co-commencement of metformin alongside antipsychotic treatment for individuals with certain risk factors. Specifically, it advocates for starting metformin when medium-risk antipsychotics are prescribed to patients aged 10 to 25 years or those with one or more cardiometabolic risk factors. Additionally, it suggests initiating metformin if a patient experiences more than a 3% increase in baseline body weight during the first year of treatment with any antipsychotic.
“This is the first evidence-based guideline to use the AGREE II framework and GRADE methods for the prevention of AIWG, which includes specific recommendations for co-commencement of metformin,” Carolan and her team explain. They also stress the importance of shared decision-making between healthcare providers and patients to ensure the guideline’s successful implementation. The guideline further proposes assessing barriers and facilitators to its uptake in clinical practice.
The researchers believe that this new approach could significantly improve the quality of life for individuals on antipsychotic medication, especially those at risk for AIWG-related health complications.
For more detailed insights, see the study published by Aoife Carolan et al in Schizophrenia Bulletin (2024). DOI: 10.1093/schbul/sbae205.