The study, published in the Aug. 4 issue of the New England Journal of Medicine, found that treatment with 200 milligrams of the drug Modafinil helped reduce the extreme sleepiness common in patients with shift-work sleep disorder and resulted in a "small but significant" improvement in study participants' work performance compared with a placebo.
Of the study participants who took Modafinil, 74 percent saw improvements in their clinical symptoms when evaluated by a physician. Overall, those taking Modafinil fell asleep faster, focused their attention for longer periods of time during night work and avoided accidents or near-accidents while commuting home, according to the study.
The study, led by Charles Czeisler, Ph.D., M.D., chief of the Division of Sleep Medicine at the Brigham and Women's Hospital and a professor of sleep medicine at Harvard Medical School, "represents the first large-scale clinical trial for patients with shift-work sleep disorders," Czeisler told Occupational Hazards.com.
"One of the first things we were able to do was document the impact of this debilitating condition on these patients in terms of their ability to stay alert and to perform on the job," Czeisler said.
Workers diagnosed with shift-work sleep disorder chronically suffer from excessive sleepiness during night work and insomnia when trying to sleep during the day. They also "miss family and social activities more frequently and have higher rates of ulcers, sleepiness-related accidents, absenteeism and depression than do night-shift workers without the disorder," according to the study.
About 5 to 10 percent of the nearly 6 million Americans who work at night suffer from shift-work sleep disorder, according to the study.
While the study concludes that Modafinil marketed as "Provigil" by its manufacturer, Frazer, Pa.-based Cephalon Inc. may be a viable treatment for shift-work sleep disorder, Czeisler added that more research is needed to identify other treatment options.
"These are profoundly sleepy patients whose conditions were improved by the treatment but still remained sleepy after treatment," he said.
Czeisler added that medication is just one element in a treatment program for shift-work sleep disorder. Working conditions, lighting and scheduling also can have a big impact on night-shift workers' alertness and performance, he said.
The Food and Drug Administration approved Provigil in January 2004 to treat the excessive sleepiness associated with shift-work sleep disorder and with obstructive sleep apnea/hypopnea syndrome, according to Cephalon.
The most frequently reported side effects of Provigil in clinical trials, according to the company, were headache, nausea, nervousness, stuffy nose, diarrhea, back pain, anxiety, trouble sleeping, dizziness and upset stomach.