The efficacy of quetiapine vs haloperidol and placebo: a meta-analytic study of efficacy

Atypical antipsychotics form a new class of treatment for psychotic disorders that offers advantages over conventional antipsychotics, such as haloperidol. Among these advantages is a lower risk of side effects-in particular movement disorders. The atypical antipsychotics that are currently commercially available are clozapine, risperidone, olanzapine, quetiapine, and ziprasidone. The focus of this report is on the efficacy of quetiapine.

A meta-analysis was performed on three placebo- and five haloperidol-controlled clinical trials of quetiapine. Efficacy was assessed using the Brief Psychiatric Rating Scale (BPRS), the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impression (CGI), and the Scale for the Assessment of Negative Symptoms (SANS). In addition, a responder analysis was performed assessing patients who demonstrated a 40% improvement on the BPRS total score.

The results showed that quetiapine was significantly (p<0.05) superior to placebo in improving psychotic symptoms. In addition, quetiapine was not significantly different from haloperidol on measures of efficacy measured by BPRS change score, but was superior to haloperidol in terms of response rate using observed case analysis (but not using last observation carried forward analysis).

This meta-analysis supports the use of quetiapine as a front-line treatment for schizophrenia.