Double-blind comparison of ziprasidone and risperidone in the treatment of Chinese patients with acute exacerbation of schizophrenia

Background: The aim of the study was to evaluate the efficacy and safety of ziprasidone versus risperidone in Chinese subjects with acute exacerbation of schizophrenia. Methods: In patients meeting the Chinese Classification of Mental Disorders criteria for schizophrenia and with a Positive and Negative Syndrome Scale (PANSS) total score ≥60 were randomly assigned to six weeks of double-blind treatment with ziprasidone 40–80 mg twice daily or risperidone 1–3 mg bid, flexibly dosed. Noninferiority was demonstrated if the upper limit of the two-sided 95% confidence interval (CI) for the difference in PANSS total score improvement from baseline in the evaluable population was smaller than the prespecified noninferiority margin of 10 units. Results: The intent-to-treat population comprised 118 ziprasidone-treated and 121 risperidone-treated subjects. Improvement (reduction) from baseline to week 6 in PANSS total score was (-35.6 [95% CI: -38.6, -32.6]) for ziprasidone and (-37.1 [95% CI: -39.9, -34.4]) for risperidone. Noninferiority was demonstrated in the evaluable population with a difference score of 1.5 [95% CI: -2.5, 5.5]. Mean prolactin levels decreased at week 6 compared with baseline for ziprasidone (-3.5 ng/mL), but significantly increased for risperidone (61.1 ng/mL; P < 0.001). More risperidone-treated subjects (14.9%) than ziprasidone-treated subjects (4.2%) reported weight gain ≥7%. Akathisia and somnolence in the ziprasidone group and akathisia and insomnia in the risperidone group were the most common side effects. Treatment-related/treatment-emergent adverse events were reported by 79.7% and 71.1% of ziprasidone-treated and risperidone-treated subjects, respectively. Conclusion: In Chinese subjects, ziprasidone was as effective as risperidone, with less weight gain and less prolactin elevation.