Seroquel and Drowsiness

Seroquel extended release version was less sedating than the rapid release version

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Sedation, like feeling drowsy or slowed down, can be a side effect of taking Seroquel. There are two forms of Seroquel. Is one form better than the other?

A recent study looked at sedation for people with bipolar taking either the extended or immediate release version of Seroquel (quetiapine).

People taking the extended release Seroquel reported less sedation during the first three hours after taking their daily dose.

"Tell your doctor about any Rx side effects."

Seroquel is an atypical antipsychotic that is approved for the treatment of schizophrenia, bipolar disorder, and depression.

Researchers, led by Robert A. Riesenberg, MD, at the Atlanta Center for Medical Research in Georgia, enrolled 134 men with bipolar disorder.

Some took the extended release version of Seroquel. Others took the immediate release version.

The researchers were looking for differences in sedation during the first few days that people were taking the drug.

The dose of Seroquel is usually ramped up slowly when people first begin taking it. Each day, the dose is increased until the effective dose is reached.

For this study, doses were increased from 50 mg/day up to 300 mg/day over 4 days.

The patients answered questions about their sedation and drowsiness over the first 14 hours after taking their daily dose of Seroquel.

They found that people reported feeling more sedated in the first three hours of taking the immediate release version of Seroquel than the extended release.

After the first three hours, people taking both versions of the drug reported the similar levels of sedation.

The authors concluded that there is less sedation after taking the extended release version of Seroquel, which may be helpful for some patients who are struggling with this side effect.

For patients who have concerns about sedation, a doctor can prescribe the appropriate dose and version of Seroquel.

This study was published October 11 in Clinical Therapeutics. This report is a Phase IV clinical trial funded by AstraZeneca.

Two of the authors on the study work for AstraZeneca, the maker of Seroquel.

Reviewed by: 
Review Date: 
October 21, 2012
Last Updated:
October 24, 2012