Drug Evaluations: Drug Evaluation Central & Peripheral Nervous Systems: ‘Seroquel’ (quetiapine): Preclinical and clinical findings of a new atypical antipsychotic

Abstract

This article first briefly reviews the preclinical findings of ‘Seroquel’ (quetiapine, Zeneca Pharmaceuticals), a novel dibenzothiazepine antipsychotic agent in late-stage clinical development, especially with respect to its potential as an atypical antipsychotic with a pharmacological profile similar to clozapine, but without the significant side-effects associated with clozapine. The rest of the article is a detailed review of the clinical studies of quetiapine completed to date. These include three placebo-controlled studies (Studies 4, 6, and 8), one open-labelled study (Study 5), and one study in which quetiapine was compared to chlorpromazine (Study 7). Details of the study designs and the efficacy, safety, and tolerability analyses are provided, and a summary of the results of each study is presented. Based on the findings in these five studies, quetiapine appears to be an effective antipsychotic agent for the treatment of both the positive and negative symptoms of schizophrenia, with efficacy that is statistically significantly superior to placebo and comparable to chlorpromazine. Quetiapine causes few extrapyramidal symptoms or acute dystonic reactions (rates are similar to placebo across the dose range), and it does not produce sustained elevations in serum prolactin. The clinical findings distinguish quetiapine from standard antipsychotics and further support its designation as an atypical antipsychotic.

Key Words:

• atypical antipsychotic
• clozapine
• quetiapine
• extrapyramidal side-effects
• prolactin levels