THE EFFICACY OF METFORMIN IN COUNTERACTING OLANZAPINE- INDUCED HYPERPROLACTINEMIA: AN OPEN-LABEL PROSPECTIVE STUDY

Abstract Background Prolactin elevation, resulting from dopamine D2 receptor antagonism, is a common side effect of antipsychotic medications. Olanzapine, an atypical antipsychotic drug, offers enhanced clinical efficacy and fewer side effects compared to typical antipsychotic drugs. Nevertheless, some studies suggest that olanzapine may still lead to an increase in prolactin levels. Aims & Objectives Our study aimed to explore the potential of metformin in managing olanzapine- induced hyperprolactinemia in patients with schizophrenia. Method A prospective study was designed to investigate the changes in prolactin levels over an eight- week metformin treatment. We enrolled thirty-one patients with schizophrenia who had been on olanzapine treatment for at least three months. These participants were initiated on metformin therapy at 1500 mg/day for eight weeks. Prolactin levels and metabolic parameters were assessed at baseline and at weeks 2, 4, 6, and 8 of the study. Results Results indicated a significant reduction in prolactin levels following eight weeks of metformin treatment, particularly in patients with elevated baseline prolactin levels. Insulin, glucose, and triglyceride levels, as well as insulin resistance, significantly decreased after metformin treatment. No significant gender differences were observed regarding the impact of metformin on prolactin levels and metabolic variables. Discussion & Conclusion This study underscores metformin's potential to address antipsychotic-induced side effects, paving the way for further research on its long-term efficacy in managing hyperprolactinemia in patients with psychiatric disorders.