Efficacy and safety of olanzapine in the treatment of schizophrenia (ESOLAS study)

Abstract

Background: To determine the efficacy and safety of olanzapine (Zalasta®/Zolrix®) in patients with schizophrenia.

Subjects and methods: The sample included 99 patients with schizophrenia according to the ICD-10 criteria. All patients were treated with olanzapine in flexible doses, with the average dose of 13.54 mg daily over an 8-week period. Efficacy measurements included Positive and Negative Syndrome Scale (PANSS), Clinical Global Impressions-Improvement Scale (CGI-I) and Clinical Global Impressions-Severity of Illness Scale (CGI-S), and Barnes Akathisia Scale. Safety measurements included weight, waist circumference, blood pressure, and heart rate. All scales and safety measurements were administered at baseline and at weeks 2, 4 and 8.

Results: After 8 weeks of treatment with olanzapine, a total of 91 patients (91.9 %) completed the study. At week 8, olanzapine treatment resulted in a statistically significant decrease in PANSS scores (from 98.99±18.93 to 66.81±15.36; p<.0001), a statistically significant decrease of positive and negative subscales scores (p<.0001), and hostility, anxiety and depression items (p<.0001). Olanzapine treatment resulted also in a statistically significant decrease of CGI-S scores to 3.21±0.7 (from markedly ill to mildly ill) at week 8 (p<.0001). A significant improvement of the patients’ overall condition towards the end of the study was observed on the CGI-I scale where 81 patients (88%) were rated by the physicians as »much/very much improved«. A significant improvement of akathisia was observed at the end of the study (p<.0001). After 8 weeks of treatment, weight, Body Mass Index, and waist circumference increased significantly (p<.0001); diastolic blood pressure significantly decreased (p<.0005) but systoli 
pressure and heart rate did not (p>.05).

Conclusion: Data from this study indicate that olanzapine is an efficient and safe therapeutic option for patients with schizophrenia.