Rosiglitazone in the assistance of metabolic control during olanzapine administration in schizophrenia: a pilot double-blind, placebo-controlled, 12-week trial.

Background: Excessive body weight gain (BWG), hyperglycemia and dyslipidemia are important side effects of olanzapine. We assessed the effects of rosiglitazone on BWG, the insulin resistance index (HOMA-IR), lipids, glycated hemoglobin and fibrinogen in olanzapine-treated schizophrenia patients.

Methods: Thirty patients taking olanzapine (10-20 mg daily for 8 months) were randomly allocated to rosiglitazone (n=15; 4 to 8 mg daily) or placebo (n=15) in a 12-week double-blind protocol. Anthropometric and biochemical variables were evaluated at baseline, weeks 6 and 12.

Results: The rosiglitazone and placebo groups gained 3.2+/-4.5 and 2.2+/-2.3 kg, respectively (p=0.65). Insulin and the HOMA-IR significantly decreased after rosiglitazone (p<0.05). Rosiglitazone did not improve the lipid profile, fibrinogen and Hb1c levels.

Conclusions: The positive impact of rosiglitazone was limited to improved glycemic control. It cannot be recommended for metabolic control during olanzapine treatment.