Adjunctive use of metformin in the treatment of atypical antipsychotic-induced weight gain

Abstract

Introduction. Atypical antipsychotics are the gold standard in the treatment of psychotic and other mental disorders due to their efficacy and tolerability. However, the relatively frequent occurrence of antipsychotic-induced metabolic syndrome has encouraged research into possible solutions to this problem, including the adjunctive use of metformin. The aim of this review article is to present a concise, comprehensive and critical overview of the aforementioned issue based on the analysis of available experimental research. Material and Methods. PubMed and Google Scholar databases were searched for relevant literature published in a fifteen-year period between 2008 and 2022. The following terms were used in the search: atypical antipsychotics, metformin, and weight gain. Only double-blind, placebo-controlled, randomized, and cohort studies were taken into consideration. Results. A total of 145 papers were analyzed, of which 10 papers with 852 subjects met the inclusion criteria. All the reviewed studies concluded that the adjunctive administration of metformin at a daily dose of 500 mg to 2,000 mg has significantly reduced atypical antipsychotic-induced weight gain, with a favorable effect on other metabolic parameters that were examined in the analyzed papers. Conclusion. Taking into account the increased cardiovascular morbidity and the consequent mortality among those who have been using atypical antipsychotics in the long term, it is necessary to assess the risks and benefits of introducing adjunctive metformin in every patient who is at risk of developing metabolic syndrome. In order to recommend the routine use of metformin in such indications, studies that would include a larger sample and a longer period of treatment are needed.