In a recent test, a drug called Provigil made night-shift workers less sleepy on the job, but it didn't wipe out the workers' sleep problems.

Provigil "reduced extreme sleepiness" and made a "small but significant" improvement in the workers' job performance when compared with a fake drug (placebo), write the researchers in The New England Journal of Medicine.

"However, the residual sleepiness that was observed in the treated patients underscores the need for the development of interventions that are even more effective," they write.

The study was sponsored by Cephalon, which makes Provigil. The researchers included Charles Czeisler, MD, PhD, of the sleep medicine divisions of Harvard Medical School and Boston's Brigham and Women's Hospital.

Provigil is used to treat excessive sleepiness caused by sleep disorders like narcolepsy and obstructive sleep apnea.

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Night-Shift Sleepiness

"Nearly 6 million Americans work at night on a permanent or rotating basis," write the researchers. They estimate that 5 percent to 10 percent of night-shift workers have shift-work sleep disorder.

Symptoms include excessive sleepiness during night work and insomnia when trying to fall asleep during the day.

The study included 209 night-shift workers. They were randomly given 200 milligram doses of Provigil or a placebo for three months. The workers didn't know which pill they got; 153 workers finished the study.

Patients were asked to report any use of over-the-counter sleep aids. Five of the 96 people taking Provigil reported using over-the-counter sleep aids, compared with one of the 108 patients taking the placebo.

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Less Sleepiness on the Job

Symptoms improved in nearly 75 percent of patients taking Provigil, compared with 36 percent of those taking the placebo.

Workers taking Provigil had fewer and shorter lapses of attention on the job. They also fell asleep a bit quicker when they tried to fall asleep, but only by about two minutes, write the researchers.

Sleepiness can be a major hazard for commuters. The number of patients who had accidents on the way home from work was 25 percent lower in the Provigil group.

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Side Effects

There were no reports of serious side effects. Headaches were the most common side effect in both groups.

The 12-week study didn't check Provigil's long-term effects.

Provigil "is of some value in the clinical management of sleepiness associated with shift-work sleep disorder," write the researchers.

"Concern remains that even with treatment with 200 milligrams of [Provigil], the excessive sleepiness observed in this underrecognized population requires the development of yet more effective therapies," they note.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Czeisler, C. The New England Journal of Medicine, Aug. 4, 2005; vol 353: pp 476-486.