Risperidone and Olanzapine Drug Outcomes Study in Korean Patients with Schizophrenia and Schizoaffective Disorder

Ahn, Yong Min; Jeong, Seong Hoon; Kim, Yong Sik; ,

Abstract

OBJECTIVE
Risperidone and Olanzapine, two representative atypical antipsychotics, both have so called 'atypicality' in common: however, some discrepancies are expected. Considering this, studies have been surprisingly rare that had directly compared the two drugs head-to-head. We compared the efficacy and tolerability of Risperidone and Olanzapine by retrospective chart review of the patients diagnosed as Schizophrenia and Schizoaffective disorder. This study was a part of international collaborative study, RODOS (Risperidone and Olanzapine Drug Outcomes study in Schizophrenia), and the total of 24 hospitals in Korea had participated in this study.
RESULTS
Among the baseline characteristics, the duration of illness was longer in Olanzapine group. Also the proportion of first admitted patients, and that of first medicated patients were both lower in Olanzapine group. Though these baseline differences have been controlled as covariates, the proportion of responsive patients was higher, and the median value of the time to effect was shorter in Risperidone group. There was no significant difference in the rate of extrapyramidal symptoms. However, the drop-out rate due to intolerance and the rate of concomitant anticholinergic usage were significantly higher in Risperidone group compared to Olanzapine group. The rate of other somatic side effects showed no between-group difference, except weight gain which was significantly more prevalent and higher in Olanzapine group.
CONCLUSION
Though Risperidone was found to be superior in efficacy, we could not draw a final conclusion since this study was a retrospective chart review without any randomization which has a severe inherent limitation. This study should not be taken as an attempt to prove one drug's superiority over the other: rather, an attempt to scrutinize each drugs' weak and strong points to provide a guideline for proper drug usage accordingly.