Medication Helps Reduce Extreme Sleepiness Among Sufferers of Shift-Work Sleep Disorder

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In approximately 5 to 10 percent of night shift workers, the sleep wake disturbance is severe enough to warrant a diagnosis of shift work sleep disorder.

Improvments in objective measures of alertness, clinical symptoms and vigilance encouraging; researchers caution that medication does not eliminate residual excessive sleepiness

Nearly six million Americans work at night on a permanent or rotating basis. Night shift-work disrupts both sleep and waking because of the misalignment of circadian rhythms and sleep-wake behavior. In approximately five- to ten-percent of night shift workers, the sleep-wake disturbance is severe enough to warrant a diagnosis of shift-work sleep disorder, which is characterized by excessive sleepiness during night work and insomnia when attempting to sleep during the daytime.

Researchers from Brigham and Women's Hospital (BWH), in this first-ever clinical trial of shift-work sleep disorder, evaluated the use of modafinil (a medication approved for Narcolepsy sufferers and residual sleepiness associated with sleep apnea) for treating sleepiness among these workers. They found that when compared to placebo, the medication improved nighttime sleep latency - the interval between the time a person attempts to fall asleep and the onset of sleep - and clinical symptoms. However, researchers caution that while some benefits were seen, patients taking modafinil continued to experience excessive sleepiness and impaired performance at night. These findings will be published in the August 4, 2005 issue of the New England Journal of Medicine.

"Shift-work sleep disorder adversely affects many working Americans. It can compromise personal safety and significantly impact quality of life," said Charles A. Czeisler, PhD, MD, chief of BWH's Sleep Medicine Division. "Individuals suffering from this disorder have limited available treatments to minimize symptoms. This study demonstrates that while modafinil can significantly improve symptoms and reduce sleep tendency during night work hours, patients remain excessively sleepy even after treatment for this sleep-wake disturbance."

Individuals with shift-work sleep disorder miss family and social activities more frequently and have higher rates of ulcers, sleepiness-related accidents, absenteeism and depression. To learn how to better treat these individuals, researchers conducted a study to evaluate the efficacy and safety of 200 mg of modafinil in patients with excessive sleepiness. In this three-month, double-blind trial, researchers randomly assigned 209 patients - adults between the ages of 18 and 60 years - to either 200 mg of modafinil or placebo, taken at the start of each shift. Night shift workers were defined as those who worked at least five night shifts for 12 hours or less, with six hours or more between 10:00 pm and 8:00 am and at least three shifts occurring consecutively. During a three-month time period, researchers measured: sleep latency through a polysomnography (a diagnostic test during which a number of physiologic variables are measured and recorded during sleep); alertness with a performance measure test; sleepiness through a self-reported sleepiness scare; and, other variables such as caffeine consumption through an electronic diary.

Researchers found the following benefits among patients who were assigned modafinil:

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* Average sleep latency improved from 2.1 minutes at baseline to 3.8 minutes at the final visit.

* Clinical symptoms, which include excessive sleepiness during night work and insomnia when attempting to sleep in the daytime improved among 74 percent of patients on modafinil versus 36 percent in the placebo group.

* Accidents or near accidents were reduced by 25 percent.

* Attentional failures were significantly reduced in both frequency and duration.

Researchers note that while these improvements are encouraging, patients treated with modafinil continued to experience excessive sleepiness and impaired performance.

Czeisler, who is also the Baldino Professor of Sleep Medicine and director of the Harvard Medical School Division of Sleep Medicine said, "Modafinil is clearly valuable in treating some of the clinical symptoms of shift-work sleep disorder. However, excessive sleepiness still remains among this population and this study demonstrates that additional research is necessary to find other effective therapies."

The study was sponsored by Cephalon, Inc., for which Czeisler serves as a paid consultant and from which the Brigham and Women's Hospital and Harvard Medical School have received research contracts, grants and unrestricted gifts.

By Brigham and Women's Hospital
This page is updated on May 11, 2013.

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