Evaluating the Effect of 8-Week Treatment With Risperidone On Fasting Blood Glucose of Patients with Schizophrenia

This study was designed to evaluate the effects of risperidone on fasting blood glucose (FBG) in patients with Schizophrenia. Seventy five non-diabetic patients with Schizophrenia (based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) entered this cross-sectional study. Patients did not receive any medications (Including risperidone) affecting serum FBG levels for at least 2 weeks prior to the initiation of the study. Patients received the mean dose of 4.5mg (range 2-12mg) risperidone for 8 weeks. Pregnant women, patients with diabetes mellitus and a history of any major heart disease were excluded from this study.Additionally, none of the patients should have received electroconvulsive therapy within 6 months prior to the initiation of the antiphsychotics.FBG levels were measured at the initiation and 8 weeks after starting risperidone. Fifty one patients completed the study. The mean FBG level was increased from 88.9mg/dL (baseline) to 94.4 mg/dL at week 8 (P =0.003). This 8-week study showed that FBG levels may increase in schizophrenic patients receiving risperidone. Measuring and monitoring FBG before the initiation and during the treatment with risperidone is suggested.