Switching from quetiapine to ziprasidone: a sixteen-week, open-label, multicenter study evaluating the effectiveness and safety of ziprasidone in outpatient subjects with schizophrenia or schizoaffective disorder.

OBJECTIVE

The objectives of this study were to evaluate the effects of switching from quetiapine to ziprasidone on weight, safety, and effectiveness

METHODS

In this study, 241 subjects with schizophrenia or schizo affective disorder who had been treated with quetiapine (≥300 mg/day) for ≥3 months with either suboptimal efficacy or poor tolerability were enrolled in a 16-week, open-label, flexible-dose trial, with a 16-week follow-up (total 32 weeks). Quetiapine was tapered and discontinued over the course of 2 weeks, while ziprasidone was titrated up and dosed at 40-80 mg b.i.d. The primary endpoint was weight change (kg) from baseline at 16 weeks. Secondary endpoints were change in waist/hip circumference, lipid profile, fasting glucose, and glycosylated hemoglobin (HbA1c). Additional secondary endpoints included changes in scores on the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impressions Improvement and Severity Scales (CGI-I and CGI-S), the Calgary Depression Scale for Schizophrenia (CDSS), the Schizophrenia Cognition Rating Scale (ScoRS), and the Global Assessment of Functioning (GAF). Safety measures included adverse event (AE) reporting and administration of the Abnormal Involuntary Movement Scale (AIMS).

RESULTS

At week 16, there was a small but statistically significant decrease in weight, with a mean change from baseline of -0.73 kg (1-sided 95% upper confidence bound=-0.33) using the last observation carried forward [LOCF] approach. There were small mean decreases in levels of total cholesterol, low density lipoprotein (LDL), and triglycerides at week 16, but no change in fasting glucose or HbA1c. At week 16, there were also significant changes indicating improvement in the secondary clinical assessments, including the PANSS scores, CGI-S, CDSS, SCoRS and GAF. There was no change in the AIMS. AEs included insomnia (12.4%), somnolence (13.7%), and nausea (9.1%).

CONCLUSION

Subjects switching from quetiapine to ziprasidone showed a small but significant decrease in weight as well as improved lipid profiles, regardless of their metabolic status and disease severity at baseline. Subjects also showed improvement in clinical symptoms and in cognitive functioning. Ziprasidone, with a comparatively neutral metabolic profile relative to other antipsychotics, may be an effective treatment alternative for patients experiencing weight gain or lack of tolerability with quetiapine.