Managing Antipsychotic-Induced Weight Gain in Schizophrenia
Antipsychotic medications, while crucial for managing schizophrenia, are frequently associated with weight gain, a factor contributing to increased morbidity and mortality in affected individuals. Professor Hasan emphasizes that this weight gain, alongside complications like Type 2 Diabetes and cardiovascular/tumor diseases, considerably impacts overall health outcomes. proactive management is thus essential, particularly during the initial stages of treatment and periods of acute illness.
A complete approach to mitigating antipsychotic-induced weight gain (AIWG) begins with consistent monitoring. The recommendation is to record a patient’s weight - without shoes and pants - before starting pharmacotherapy and at every subsequent outpatient appointment. Crucially, patients and their families should be informed about the potential for weight gain and its associated health risks.
Intervention thresholds are suggested at a weight gain of 3-5%. Initial steps involve lifestyle modifications, including dietary advice focusing on portion control, encouragement of physical activity, and participation in nutrition and movement programs. If these measures prove insufficient,dose reduction of the triggering antipsychotic or switching to a different medication should be considered.In some cases, adding a weight-stable or weight-reducing medication may be appropriate.
Understanding the AIWG potential of different antipsychotics is vital. Clozapine and olanzapine carry the highest risk, while haloperidol, ziprasidone, aripiprazole, and lurasidone are associated with the lowest risk. Other antipsychotics fall on a spectrum between these extremes.Decisions regarding dose adjustments or medication changes must be individualized, taking into account the severity of the illness, treatment response, history of relapse, and any co-occurring substance use.
Metformin as a Preventative and Treatment Option
Metformin has emerged as an effective tool in managing AIWG. The 2019 S3 guideline for schizophrenia recommends its off-label use for AIWG treatment, and increasingly, international guidelines suggest preventative administration of metformin alongside antipsychotics.
A typical metformin dosage schedule involves starting with 500mg in the morning during the first week, increasing to 500mg twice daily in the second week. dosage can then be gradually increased, based on effectiveness and tolerability, up to a maximum of 2,000mg daily. Gastrointestinal side effects are common, and patients must be fully informed about the off-label nature of the treatment, as well as clarifying cost coverage with their health insurance provider.
GLP-1 Analogues: A Limited Option
GLP-1 analogues like Semaglutide and Liraglutide demonstrate significant potential for weight loss and are recommended in international literature for preventing and treating AIWG in specific cases.However, their use is currently limited in Germany due to a lack of reimbursement. Professor Hasan also highlights ongoing concerns regarding the safety and tolerability of GLP-1 analogues, particularly in individuals with serious mental illnesses and complex medication regimens.
given the established safety profile, extensive research, and affordability of metformin, it remains the primary intervention for AIWG. GLP-1 analogues may be considered as an exception for patients who already meet the criteria for their approved indications.
(Source: Hasan A.PPT 2025; 32: 89-97; doi: 10.52778/ppt20250008)
