An Inter-Ethnic Comparison Study of Ziprasidone Plasma Levels, Dosage and Clinical Response in Patients with Schizophrenia

OBJECTIVE: The aim of this study was to investigate ziprasidone plasma concentration, daily dose and clinical efficacy and safety in Han Chinese and Mongolian patients with first-episode schizophrenia. METHODS: A total of 123 inpatients affected by schizophrenia were recruited from the Mental Health Center of Inner Mongolia in China. Ziprasidone plasma concentration, clinical efficacy and side effects were systematically evaluated at baseline, and at 1, 2, 4, and 6 weeks. Metabolic measures such as changes in weight, body mass index (BMI), fasting blood glucose (FBG), triglycerides, and cholesterol, were also recorded. RESULTS: 90 patients completed the study. Compared with Han patients, on average, Mongolian patients received a significantly higher ziprasidone dosage for adequate symptom control during the 6-week period and had a lower plasma concentration-to-dose ratio. The Mongolian patients also experienced greater increases in weight and BMI. No significant differences between the two ethnic groups were found in the rate of reduction in the Positive and Negative Syndrome Scale (PANSS) score, Treatment Emergent Symptom Scale (TESS) total score, FBG, triglycerides, cholesterol or Q-Tc interval. CONCLUSION: Compared to Han Chinese patients, Mongolian patients appeared to have increased ziprasidone clearance and require higher doses to achieve effective treatment for schizophrenia.