NR283
Monday, May 23, 3:00 p.m.-5:00 p.m.

Time to All Cause Discontinuation Following Randomization to Open-Label Olanzapine, Risperidone, or Conventional Antipsychotic Treatment for Schizophrenia

Haya Ascher-Svanum, Ph.D., Department of Outcomes
Research, Eli Lilly and Company, Lilly Corporate Center,
Indianapolis, IN 46285; Allen W. Nyhuis, M.A., Sandra L. Tunis,
Ph.D., Michael Stevens, M.D.

Educational Objectives:
At the conclusion of this session, the participant should be able to recognize the usefulness of ‘‘time to all-cause medication discontinuation’’ as an important measure of treatment effectiveness, and that olanzapine appears to be associated with significantly longer time to all-cause medication discontinuation compared to treatment with risperidone or conventional antipsychotics,
regardless of potency level.

Summary:
Objective: To compare olanzapine, risperidone, and conventional antipsychotics on time to all-cause medication discontinuation in the treatment of schizophrenia.
Methods: Data were from a randomized, open-label, one-year effectiveness trial conducted in the U.S. between 5/1998 and 9/2002. Patients randomized to olanzapine (N=222), risperidone (N=217), or conventional antipsychotics (N=209) of low, medium, or high potency level were compared on time to all-cause medication discontinuation. Post hoc survival analyses were used to compare the treatment groups on time to all-cause medication discontinuation during the one year following randomization.

Results: The one-year survival rate was significantly higher for olanzapine (55%) than risperidone-treated patients (47%, p=.006). Survival rate for olanzapine-treated patients was significantly (p<.001) higher than conventional antipsychotics of high, medium, or low potency levels, and compared with perphenazine, a medium potency conventional antipsychotic (32%). Survival rate for risperidone-treated patients was significantly (p<.01) higher than conventionals of high or medium potency, but did not significantly differ from conventionals of low potency or perphenazine.

Conclusion: In this randomized, open-label study, patients randomized to olanzapine had significantly longer time to all-cause medication discontinuation compared to patients treated with risperidone or conventional antipsychotics, regardless of potency level. Findings suggest that atypical antipsychotics differ on this important effectiveness measure.

References:
1. Stroup TS, McEvoy JP, Swartz MS, Byerly MJ, Glick ID, Canive JM, McGee MF, Simpson GM, Stevens MC, Lieberman JA: The National Institute of Mental Health Clinical Antipsychotic
Trials of Intervention Effectiveness (CATIE) project: schizophrenia trial design and protocol development. Schizophr Bull 2003; 29:15-31.
2. Hugenholtz GWK, Heerdink ER, Nolen WA, Egberts ACG: Less medication switching after initial start with atypical antipsychotics. European neuropsychopharmacology 2004; 14:1-5.