Can Metformin Counteract Antipsychotic-Induced Hyperprolactinemia? New Evidence Emerges

For this purpose, the researchers conducted a systematic search across PubMed, CNKI, Embase, Cochrane, and Web of Science up to January 31, 2024, to identify randomized controlled trials (RCTs) assessing the impact of metformin on prolactin levels in patients with schizophrenia. The extracted data were analyzed using a random-effects meta-analysis to synthesize the findings.

Key findings:

• The meta-analysis included 10 randomized controlled trials with 1,046 participants, where 584 received metformin, and 462 were in the control group (placebo or no treatment).
• Metformin significantly lowered prolactin levels compared to the control group, with an average reduction of 34.88 ng/mL.
• Higher doses (1,500 mg), shorter treatment durations (less than 24 weeks), higher BMI (above 25 kg/m²), and longer illness duration (more than one year) were linked to greater reductions in prolactin levels.
• Metformin was well tolerated, with no significant increase in adverse events or treatment discontinuation compared to the control group.

The authors of this meta-analysis highlight the potential of metformin as a therapeutic option for managing antipsychotic-induced hyperprolactinemia in patients with schizophrenia. Their findings suggest that metformin is well tolerated and particularly effective at higher doses and shorter treatment durations in individuals with a higher BMI and those with a longer duration of illness. However, the researchers emphasize the need for cautious interpretation due to the high heterogeneity across studies.

They recommend further investigations to explore demographic and clinical factors that may influence treatment response, ultimately optimizing metformin’s role in managing hyperprolactinemia in this patient population.

Reference:

Goh, K. K., Chen, H., & Lu, L. Evaluating the efficacy of metformin in reducing hyperprolactinemia among patients with schizophrenia: A meta-analysis of randomized controlled trials. Journal of Psychopharmacology. https://doi.org/10.1177/02698811251326945