AstraZeneca received approval from the FDA for Seroquel XR Extended-Release Tablets, a once-daily medicine for the treatment of schizophrenia in adult patients. The Seroquel XR development program was based on the need for a wider choice of medicines that offer convenient once-daily dosing.

Schizophrenia is a serious brain disorder with symptoms including distorted perceptions of reality, hallucinations and delusions, illogical thinking, and flat or blunted emotions, and affects more than two million American adults.

The FDA approval was based on clinical data showing effectiveness of the extended-release tablets at doses of 400, 600, and 800 mg/day. The trial was a placebo-controlled study of patients experiencing an acute exacerbation of symptoms of schizophrenia with efficacy assessed using the Positive and Negative Syndrome Scale (PANSS) ratings scale. After six weeks of treatment, patients recorded a significant improvement in PANSS total scores from baseline for Seroquel XR doses of 400, 600, and 800 mg/day, compared with placebo-treated patients. Seroquel XR was generally well tolerated. The most commonly observed adverse reactions associated with the use of Seroquel XR were dry mouth, somnolence, dizziness, and dyspepsia.