A 24-week, multicenter, open-label, randomized study to compare changes in glucose metabolism in patients with schizophrenia receiving treatment with olanzapine, quetiapine, or risperidone.

OBJECTIVE: This randomized, 24-week, flexible-dose study compared changes in glucose metabolism in patients with DSM-IV schizophrenia receiving initial exposure to olanzapine, quetiapine, or risperidone. METHOD: The hypothesized primary endpoint was change (baseline to week 24) in area under the curve (AUC) 0- to 2-hour plasma glucose values during an oral glucose tolerance test (OGTT); primary analysis: olanzapine versus quetiapine. Secondary endpoints included mean change in AUC 0- to 2-hour plasma insulin values, insulin sensitivity index, and fasting lipids. The first patient enrolled on April 29, 2004, and the last patient completed the study on October 24, 2005. RESULTS: Mean weight change (kg) over 24 weeks was +3.7 (quetiapine), +4.6 (olanzapine), and +3.6 (risperidone). Based on data from 395 patients (quetiapine, N = 115 [mean dose = 607.0 mg/day], olanzapine, N = 146 [mean dose = 15.2 mg/day], and risperidone, N = 134 [mean dose = 5.2 mg/day]), mean change in AUC 0- to 2-hour glucose value (mg/dL x h) at week 24 was significantly lower for quetiapine versus olanzapine (t = 1.98, df = 377, p = .048). Increases in AUC 0- to 2-hour glucose values were statistically significant with olanzapine (+21.9 mg/dL x h, 95% CI = 11.5 to 32.4 mg/dL x h) and risperidone (+18.8 mg/dL x h, 95% CI = 8.1 to 29.4 mg/dL x h), but not quetiapine (+9.1 mg/dL x h, 95% CI = -2.3 to 20.5 mg/dL x h). AUC 0- to 2-hour insulin values increased statistically significantly with olanzapine (+24.5%, 95% CI = 11.5% to 39.0%), but not with quetiapine or risperidone. Reductions in insulin sensitivity index were statistically significant with olanzapine (-19.1%, 95% CI = -27.9% to -9.3%) and risperidone (-15.8%, 95% CI = -25.1% to -5.4%), but not quetiapine. Total cholesterol and low-density lipoprotein levels increased statistically significantly with olanzapine (+21.1 mg/dL, 95% CI = 13.0 to 29.2 mg/dL, and +20.5 mg/dL, 95% CI = 13.8 to 27.1 mg/dL, respectively) and quetiapine (+13.1 mg/dL, 95% CI = 4.3 to 21.9 mg/dL, and +13.3 mg/dL, 95% CI = 6.1 to 20.5 mg/dL, respectively), but not risperidone. Statistically significant increases in triglycerides (+30.9 mg/dL, 95% CI = 10.9 to 51.0 mg/dL), total cholesterol/high-density lipoprotein (HDL) ratio (0.5, 95% CI = 0.2 to 0.8), and triglyceride/HDL ratio (0.3, 95% CI = 0.0 to 0.6) were observed with olanzapine only. CONCLUSION: The results indicate a significant difference in the change in glucose tolerance during 6 months' treatment with olanzapine versus quetiapine, with significant reductions on olanzapine and risperidone, but not quetiapine; these differential changes were largely explained by changes in insulin sensitivity. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00214578.

Quetiapine and long-term weight change: a comprehensive data review of patients with schizophrenia.

BACKGROUND: To assess the magnitude and pattern of weight change during long-term treatment with the atypical antipsychotic quetiapine. METHOD: Data were collected from patients with a DSM-IV diagnosis of schizophrenia treated with quetiapine in the AstraZeneca clinical trials program from July 1993 to May 1999. Weight changes in patients treated for 12, 52, and 104 weeks were analyzed; the primary parameter was the change in weight at week 52. RESULTS: In total, 352 patients were treated with quetiapine for 52 weeks. The mean weight gain at this timepoint was 3.19 kg; median weight gain was 2.5 kg. Overall, 37% of patients gained >or= 7% of their baseline body weight; however, the degree of weight gain was inversely related to baseline body mass index in this cohort. In patients treated with < 200 mg/day of quetiapine, mean weight gain was 1.54 kg, compared with 4.08 kg for 200 to 399 mg/day, 1.89 kg for 400 to 599 mg/day, and 3.57 kg for >or= 600 mg/day; median weight gain was 0.95 kg, 3.40 kg, 2.00 kg, and 3.34 kg, respectively. Analysis of longitudinal weight changes indicated that most weight gain (> 60%) occurred within the first 12 weeks of quetiapine treatment, with modest changes after 6 months. CONCLUSIONS: Long-term treatment with quetiapine monotherapy is associated with moderate weight gain. Most weight gain occurs within the first 12 weeks of treatment and has no clear dose relationship.