Zyprexa (olanzapine) was more effective on discontinuation rate in patients with schizophrenia than were other medications studied, according to the conclusions of the Clinical Antipsychotic Trial of Intervention Effectiveness (CATIE).

CATIE was designed to evaluate the overall clinical effectiveness of antipsychotics in the treatment of schizophrenia, as measured by any-cause medication discontinuation, a measure that integrates both the patients' and the doctors' judgment of how well a medication works, its safety and how well the patient tolerates the treatment.

Robert Baker, medical director, US neuroscience, Eli Lilly and Company said, "The study also had favourable findings for Zyprexa in terms of duration of successful treatment and risks of rehospitalization. This is important to patients and doctors because research shows that patients who stay on their medication generally have greater improvement in symptoms, reducing hospitalization and costs, and may function better in their daily lives."

CATIE found that for Zyprexa the average time to discontinuation was 9.2 months as compared with 4.6 months for quetiapine, 4.8 months for risperidone, 3.5 months for ziprasidone and 5.6 months for perphenazine. The differences were statistically significant for olanzapine compared with risperidone and quetiapine, but not for perphenazine or ziprasidone.

Zyprexa is indicated in the United States for the short- and long-term treatment of schizophrenia, acute mixed and manic episodes of bipolar I disorder, and maintenance treatment of bipolar disorder. Since Zyprexa was introduced in 1996, it has been prescribed to more than 18 million people worldwide.