Many outpatients with schizophrenia experience severe metabolic side effects such as metabolic syndrome that occurs frequently in the treatment with some atypical antipsychotics that especially with clozapine and olanzapine.

To determine whether antipsychotic-associated metabolic abnormalities identified through intensive monitoring can be changed by switching from olanzapine medication to ziprasidone in patients with schizophrenia.

Stable outpatients with metabolic side effects on olanzapine (n=20) therapy were switched to a flexible-dose trial of ziprasidone (40-160 mg/day) in this 13-week naturalistic study. All patients underwent an extensive metabolic evaluation at baseline, at 6 weeks, and at 13 weeks post switch. Metabolic abnormalities included the following medical complications: new onset diabetes impaired fasting glucose, impaired glucose tolerance, metabolic syndrome according to various definitions, and dyslipidemia. After 13 weeks of treatment with ziprasidone (mean daily dose 136.4 mg), there was a significant decrease in body weight, body mass index, and waist circumference. There was a significant reduction in fasting glucose, fasting insulin, and serum lipids levels (cholesterol, triglycerides, low-density lipoprotein (LDL), LDL/HDL, Chol/HDL, and non-HDL cholesterol). The metabolic syndrome was reversed in 70% of patients at 3 months.

Switching stable outpatients with schizophrenia from olanzapine to ziprasidone was generally well tolerated and was associated with improvements at 13 weeks. Results support the reversibility of olanzapine-induced metabolic abnormalities when detected early and followed by a switch to ziprasidone.