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

Since 1990 novel antipsychotics have been available to treat schizophrenia. Risperidone and olanzapine have emerged as the two most popular members of this class. The current report aims to synthesize the clinical trial data currently available on these two novel antipsychotics and compare them with conventional products in terms of efficacy and safety.

Published randomized clinical trials, which included a risperidone or olanzapine arm, were sought through the MEDLINE, EMBASE and PSYCLIT databases. Trials were only excluded due to reporting failures or design incompatibilities (not randomized). A random effects approach was applied to compare information across trials, and meta-regression was used to compare product categories and gain insight into patient factors related to clinical outcomes. Outcome variables measured were total Positive and Negative Symptom Scale (PANSS) score, withdrawals due to inefficacy and use of medication for extrapyramidal symptoms (EPS).

Risperidone and olanzapine offer advantages over conventional products in terms of both efficacy and safety. Of the two novel antipsychotics studied, the benefits of risperidone were clearer than those with olanzapine in terms of efficacy; this could not be assessed for safety due to inconsistencies in the reporting of extrapyramidal symptoms between studies.

Patients receiving novel antipsychotics, particularly risperidone, are likely to gain improved control of symptoms of schizophrenia and are less likely to require medication to counteract extrapyramidal symptoms than patients receiving conventional neuroleptics.