Drug curbs daytime sleepiness in Parkinson's

NEW YORK (Reuters Health) - Taking the drug sodium oxybate at night seems to help curb excessive daytime sleepiness in patients with Parkinson's disease, according to study findings.

Sodium oxybate is approved in the US for the treatment of excessive daytime sleepiness in patients with narcolepsy, a condition that causes people to fall asleep involuntarily, and for the treatment of cataplexy, a sudden weakness in the muscles that accompanies narcolepsy.

Nighttime sleep disturbances and excessive daytime sleepiness are common in people with Parkinson's disease, Dr. William G. Ondo from Baylor College of Medicine in Houston, Texas, and colleagues point out in the latest issue of Archives of Neurology.

The researchers examined the safety and effectiveness of sodium oxybate given at night in 30 patients with Parkinson's disease and excessive daytime sleepiness and unsatisfactory sleep (usually insomnia). Three patients dropped out of the study due to dizziness and depression, so 27 patients completed the study.

According to Ondo and colleagues, significant improvements were observed in daytime sleepiness and in levels of fatigue and overall sleep quality.

More than two-thirds of the patients chose to continue sodium oxybate therapy at the study's conclusion.

"Given the robust efficacy and good tolerability of the study drug and the lack of effective treatment for excessive daytime sleepiness in patients with Parkinson's disease," further controlled trials are justified, the investigators conclude.

SOURCE: Archives of Neurology, October 2008.