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

Objective: This study was designed to evaluate the effects of risperidone on fasting blood glucose (FBG) in patients with Schizophrenia . Method: 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. Results: 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. Conclusion: Measuring and monitoring FBG before the initiation and during the treatment with risperidone is suggested.