The clinical value of risperidone and olanzapine: A meta-analysis of efficacy and safety

Introduction: Since 1990 novel antipsychotics have been available to treat schizophrenia. Risperidone and olanzapine have emerged as the two most popu lar members of this class. The current report aims to synthesize the clinic al trial data currently available on these two novel antipsychotics and com pare them with conventional products in terms of efficacy and safety. Methods: Published randomized clinical trials, which included a risperidone or olanzapine arm, were sought through the MEDLINE, EMBASE and PSYCLIT dat abases. Trials were only excluded due to reporting failures or design incom patibilities (not randomized). A random effects approach was applied to com pare information across trials, and meta-regression was used to compare pro duct categories and gain insight into patient factors related to clinical o utcomes. Outcome variables measured were total Positive and Negative Sympto m Scale (PANSS) score, withdrawals due to inefficacy and use of medication for extrapyramidal symptoms (EPS). Results: Risperidone and olanzapine offer advantages over conventional prod ucts in terms of both efficacy and safety. Of the two novel antipsychotics studied, the benefits of risperidone were clearer than those with olanzapin e in terms of efficacy; this could not be assessed for safety due to incons istencies in the reporting of extrapyramidal symptoms between studies. Conclusion: Patients receiving, novel antipsychotics, particularly risperid one, are likely to gain improved control of symptoms of schizophrenia and a re less likely to require medication to counteract extrapyramidal symptoms than patients receiving conventional neuroleptics.