Source: J Indian Med Assoc  |  Posted 7 years ago

By Jill Stein

SAN FRANCISCO, CA -- April 30, 2004 -- Olanzapine is less likely to cause tardive dyskinesia (TD) than conventional antipsychotics in acutely psychotic or agitated older patients, according to data released on April 28th here at the American Academy of Neurology 56th Annual Meeting.

Bruce Kinon, MD, Medical Advisor, United States Medical Neurosciences, Lilly Research Laboratories, presented results in 193 patients without TD who had been randomised to olanzapine 2.5 to 20 mg/day or conventional antipsychotic therapy dosed per label.

All subjects underwent a 6-week drug-tapering/drug-initiation period, followed by reassessment of TD. Patients who remained without TD after the first 6 weeks were treated with olanzapine for up to 1 year.

The primary analysis was time to TD incidence, defined as rating on the Abnormal Involuntary Movement Scale (AIMS) of either of the following: A): moderate severity (greater than or equal to 3) in 1 body region or mild severity (greater than or equal to 2) in 2 or more body regions; or B) moderate severity (greater than or equal to 3) in 1 body region alone.

Results showed that patients in the conventional antipsychotic group were at greater risk of presumptive TD than patients in the olanzapine group for criteria A or B (P <.05).

The incidence of persistent TD (symptoms persisting for at least 1 month) was lower overall, and differed between olanzapine and conventional antipsychotic treatment groups for criterion B (moderately severe symptoms [P <.05]),

Dr. Kinon said that the lower risk for developing dyskinetic symptoms in elderly patients following treatment with olanzapine supports the overall low extrapyramidal-symptom profile of olanzapine, which has been observed in prior studies.

Tardive dyskinesia is an abnormal involuntary movement disorder that can develop in patients chronically treated with antipsychotic drugs.

The incidence rate for the development of TD is roughly 5% per year of exposure to conventional antipsychotic drugs, although the 1-year incidence rate can be 25% or greater in elderly patients.

This study was supported by Eli Lilly and Company, Indianapolis, Indiana, United States.

[Presentation title: "Incidence of Presumptive Tardive Dyskinesia in Elderly Patients Treated with Olanzapine or Conventional Antipsychotics." Abstract #P04.108]