Ziprasidone as an adjuvant for clozapine- or olanzapine-associated medical morbidity in chronic schizophrenia.

Objective: This study sought to examine the effect of ziprasidone on olanzapine or clozapine-associated medical morbidity such as insulin resistance, diabetes mellitus (DM) and impaired fasting glucose, obesity, and hyperlipidemia in patients with schizophrenia or schizoaffective disorder.

Method: This was a 6-week, open label trial of ziprasidone 160 mg/day added to a stable dose of olanzapine or clozapine in 21 schizophrenia or schizoaffective patients with DM, impaired fasting glucose, or insulin resistance.

Results: Ten olanzapine-treated subjects and 11 clozapine-treated subjects were enrolled in the study. There were no significant differences between the two groups at baseline for age, gender, education, ethnicity, BMI, cholesterol levels, or fasting glucose. At week 6, there were no significant changes in weight, BMI, cholesterol levels, or fasting glucose. There was no significant difference in psychotic, negative, or depressive symptoms. QTc significantly increased at week 2 but not at week 6.

Conclusions: The addition of 160 mg/day of ziprasidone was well tolerated but did not produce significant improvement in fasting glucose, insulin resistance, hyperlipidemia or lead to weight loss in olanzapine- or clozapine-treated subjects with schizophrenia or schizoaffective disorder.