P-1075 - Metformin against antihistamine-induced weight gain in psychiatric in-patients

Introduction: Weight gain is a common side effect of antipsychotic and antidepressive drug therapy, difficult both to avoid and to treat. In several randomized controlled studies, add-on treatment with metformin has been demonstrated to reduce olanzapine-induced weight gain. In our department of psychiatry and psychotherapy, metformin has been used against antihistaminic-drug-induced weight gain since 2008. Objectives: Primary: To demonstrate the efficacy of metformin for prophylaxis of antihistaminic-drug-induced weight gain in a cohort of psychiatric in-patients under naturalistic conditions. Secondary: To identify side-effects of add-on metformin therapy in non-diabetic psychiatric in-patients. Methods: Retrospective case-control analysis of in-patient charts from 3400 psychiatric therapies between 2008 and 2010 at Ulm University Department of Psychiatry and Psychotherapy III. Cases were identified on the basis of metformin prescription without a diagnosis of diabetes. Controls were matched for gender, age, BMI, diagnosis, and drug treatment. Evaluation will be performed with descriptive statistics, covariance analyses and mixed models. Results: No serious side effects could be attributed to metformin therapy on the basis of the charts reviewed. Further results will be presented at the meeting. Conclusions: Metformin appears to be safe with regard to side effects in psychiatric in-patients taking anti-histaminic drugs. [ABSTRACT FROM AUTHOR]