Analysis of data pooled from two 12-week, double-blind, randomized, placebo-controlled trials indicates that quetiapine is effective as monotherapy for acute mania associated with bipolar I disorder, according to a presentation at the annual meeting of the American Psychiatric Association.

Of the 604 total patients, 48.1 percent of quetiapine patients achieved a response (defined as greater than 50 percent decrease from baseline Young Mania Rating Scale score) compared with 31.3 percent of patients given placebo.

"These studies present a fair evaluation of the ability of quetiapine fumarate to manage the symptoms of acute mania in patients with bipolar disorder," said Eduard Vieta, MD, PhD, Director of Bipolar Disorders Program, University of Barcelona, Spain.

In the two trials, the adult patients experiencing a manic episode were assigned to receive quetiapine fumarate (up to 800 mg/day), placebo, lithium, or haloperidol, with lithium or haloperidol serving as controls to assess assay sensitivity. The primary endpoint was change from baseline Young Mania Rating Scale total score at day 21 of treatment.

Patients who responded to quetiapine were receiving an average dose of 575.5 mg/day by the third week of treatment. In addition to the finding on response rate at 3 weeks, 60.8 percent of quetiapine patients completed the trial compared with only 38.9 percent of patients on placebo. Common adverse events in patients taking quetiapine included insomnia, dry mouth, and somnolence.