Schizophrenia patients who switch from olanzapine, risperidone, or a conventional antipsychotic agent to ziprasidone are able to lose substantial weight over a year as well as improve their cholesterol and triglyceride levels, according to a presentation at the American Psychiatric Association meeting.

The data represent a total of 270 patients who participated in three identically designed 1-year-long trials: Patients who completed 6 weeks of treatment and were clinically stable were then eligible for an additional 52-week extension study in which ziprasidone was continued.

“The results of these studies suggest that switching to Geodon (ziprasidone) can help to reverse the adverse effects on weight and lipids seen with these agents," noted lead investigator, Peter J. Weiden, MD. “Weight loss was progressive and persistent, while the lipid changes seen early in the study were sustained throughout the 1-year study period.”

The amount of weight loss was related to the amount of time patients had been discontinued from their previous medication. Analysis showed that average weight loss at 1 year was 22 pounds in patients switched from olanzapine and 15 pounds in patients switched from risperidone.

“A reduction in weight and lipids of the magnitude observed in these studies may be associated with significantly reduced cardiovascular and metabolic-related events such as heart disease and diabetes,” said Harold E. Lebovitz, MD.

These findings come at a time when there is growing concern around the link between second generation antipsychotics and increased risks for obesity, diabetes, and lipid abnormalities. A recent consensus statement issued by a panel of experts, including representatives of the American Diabetes Association and the American Psychiatric Association found that second generation (or atypical) antipsychotics appear to differ significantly in their risks for weight gain and diabetes.

In addition to weight loss, significant reductions in cholesterol and triglycerides were seen in patients switched to ziprasidone. These benefits occurred within the first 6 weeks after transition and were sustained for the next year. For example, there was an average reduction of 18 mg/dL cholesterol and a 55 mg/dL triglyceride in patients switched from olanzapine. A similar pattern, but with a lower magnitude of lipid benefits, was seen among patients switched from risperidone.

Although ziprasidone appears to have a relative advantage in its metabolic profile, ziprasidone has a greater capacity to prolong the QTc interval than several other antipsychotics, and thus it may not be the first-line choice for some patients, including those with a history of cardiac arrhythmia or known cardiac disease.