AstraZeneca's Seroquel "as effective as Risperdal," QUARTZ study

Anglo-Swedish drug major AstraZeneca says that its antipsychotic Seroquel (quetiapine fumarate) demonstrated similar levels of efficacy to compared to Janssen-Cilag's Risperdal (risperidone) among schizophrenics completing an eight-week treatment course. The study results, which were recently published in the Journal of Clinical Psychiatry, show that, among Seroquel-treated patients, a significantly lower rate of extra-pyramidal symptoms was seen, and mean prolactin levels were not raised from baseline.

Improvements with quetiapine and risperidone were similar on PANSS total, PANSS response rates, CGI-C and cognitive function, and around half the patients on each medicine discontinued before completing eights weeks of treatment (54.4% versus 49.9%, respectively). In the Seroquel-treated group, somnolence was more common (26% vs 20%) although rates of EPS were lower (13% vs 22%), while prolactin levels were not elevated compared to baseline (decrease of 11.5ng/mL on quetiapine vs a rise of 35.5ng/mL with risperidone).

Jeffrey Lieberman of Columbia University, USA, who supervized the analysis of the data, said that "quetiapine had similar overall efficacy to risperidone, and both treatments improved cognitive and social functioning, but tolerability profiles were different," a significant factor in treatment adherence.