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Olanzapine, Ziprasidone Compared in Long-term Efficacy and Tolerability Trial
"Prevailing sentiment which suggests that all antipsychotics have similar efficacy can be misleading, so it is important to perform these types of studies to help us understand more about the differences in efficacy of various medications," said Stephen M. Stahl, M.D., Chairman of the Neuroscience Education Institute and professor of psychiatry, University of California at San Diego (UCSD). "Long-term efficacy and tolerability are key issues in the treatment of schizophrenia and some medications work better than others in different patients. It is important that patients have all of these medications available to them because they are not the same," he added.
After 28 weeks of randomized, double-blind treatment, the study showed that Zyprexa was superior for the treatment of schizophrenia:
- Long-term treatment with Zyprexa resulted in significantly better improvement in treating positive symptoms (delusions and hallucinations), as well as negative symptoms (diminished emotion, lack of interest and depressive signs), on all efficacy measures. Clear separation on positive and negative symptoms began as early as week 3 and was sustained out to 28 weeks on the Positive and Negative Syndrome Scale (PANSS) total and subscales.
- Significantly more Zyprexa patients completed the study (59.6% vs. 42.4%).
- Significantly more Zyprexa patients responded positively to treatment (58.6% vs. 42.5%).
- For those patients who responded at 8 weeks, Zyprexa patients were significantly more likely to maintain their response throughout the 28 weeks without relapse than Geodon patients (81.6% vs. 62.8%).
- Zyprexa was significantly better on the CGI-I scale (Clinical Global Impression-Improvement) at week 3 and most other time points, including week 28. The CGI-I scale is the clinician's assessment of improvement in a patient's symptoms.
- A significantly greater proportion of Geodon patients required a dose reduction due to side effects during the trial than Zyprexa patients (26.9% vs. 14.8%).
- Geodon patients required significantly more benzodiazepines (53.5%) and anticholinergics (15.5%) than Zyprexa patients (40.4% and 7.2%, respectively). Benzodiazepines are additional medications that may be given to people with schizophrenia to treat agitation or anxiety; anticholinergics may also be added to treatment to control tremors or other movement disorders.
"This study gives hope, not only to people who suffer from schizophrenia, but to their caregivers, as well," said Alan Breier, MD, Vice President, Pharmaceutical Products, Eli Lilly and Company. "The tolerability and superior efficacy of Zyprexa, as shown in this study, contributes to the development of a stronger therapeutic alliance that supports doctors in helping their patients reach their individual potential."
The study enrolled 548 patients with DSM-IV-defined schizophrenia, with 277 patients receiving Zyprexa in a flexible dose range of 10 to 20 mg/day and 271 patients receiving Geodon in a flexible dose range of 80 to 160 mg/day. The primary efficacy measure was the patients' mean change from beginning of the study to endpoint on the Positive and Negative Syndrome Scale (PANSS) total score. Response to treatment was defined as a 30 percent improvement in the PANSS total at week 8. Safety was evaluated by recording treatment-emergent adverse events and measuring vital signs and weight.
Several adverse events were reported more frequently by patients treated with Geodon than by patients treated with Zyprexa, including aggravated psychosis (4.4 percent vs. 1.4 percent), insomnia (22.1 percent vs. 6.9 percent), vomiting (9.2 percent vs. 4.0 percent), anorexia (2.6 percent vs. 0.4 percent), painful muscle contractions called dystonia (2.2 percent vs. 0.0 percent) and hypotension, or low blood pressure. (1.8 percent vs. 0.0 percent). The most common adverse events reported more frequently during Zyprexa treatment than during Geodon treatment were increased appetite (7.2 percent vs. 2.6 percent for Geodon) and increased weight (12.6 percent vs. 1.8 percent).
Schizophrenia is a severe and debilitating psychosis often characterized by acute episodes of delusions (false beliefs that cannot be corrected by reason), hallucinations (usually in the form of non-existent voices) and long-term impairments such as diminished emotion, lack of interest and depressive signs and symptoms. It is usually associated with a disruption in social and family relationships.
Schizophrenia is the most common severe mental illness. More than 2 million Americans adults have the disease, with more than 100,000 new cases reported each year. Symptoms of schizophrenia usually begin to appear in the teenage years or early to mid-twenties.