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July 13, 2000 -- As many as 38% of people report having difficulty falling asleep or staying awake during the day, statistics show, and many are taking herbal preparations to help them cope with these sleep disorders.
But while some herbs or dietary supplements may work to promote deeper sleep or daytime alertness, others have not been thoroughly studied, and some may even be dangerous, according to a study published in the journal Sleep Medicine Reviews.
Close to 40% of American adults say that daytime sleepiness interferes with their daily activities for at least a few days a month, and about 20% say it affects their daily activities a few days a week, according to a 1998 poll cited in the study.
Other surveys have found that 27% of Americans report using complementary medicines for fatigue, and 26% have used them for insomnia.
The popularity of these remedies prompted researchers -- led by Charlotte Gyllenhaal, a research assistant and professor at the University of Illinois at Chicago's College of Pharmacy -- to review the medical literature on herbal sedatives and stimulants commonly used by people with sleep problems.
According to the National Sleep Foundation in Washington, excessive daytime sleepiness (EDS) occurs when someone feels very drowsy during the day and has an overwhelming urge to fall asleep, even after getting enough nighttime sleep. People with EDS frequently doze or fall asleep in situations where they want to be fully alert, such as when driving or operating hazardous machinery.
Many people with the disorder turn to caffeine and caffeine-containing herbs such as guarana, kola nut, and yerba mate; ephedrine-containing herbs such as ephedra (also called ma huang), Indian sida and bitter orange; or other herbs, including yohimbe and ginseng, to stay awake.
While caffeine and other herbal stimulants may, in fact, decrease sleepiness, "people may place themselves in jeopardy by using these substances to disregard their biological sleep need or to control the symptoms of a more serious sleep disorder," Gyllenhaal and colleagues write.
Yohimbe, an herbal stimulant with reported aphrodisiac effects can have side effects such as nausea, vomiting, sweating, and spikes in blood pressure. People with kidney, heart, or liver disease; ulcers; glaucoma; or diabetes should avoid it, the researchers say.
Stimulants containing the Asian herb ephedra and its active ingredient ephedrine may cause side effects ranging from chest pain and anxiety to heart attack and stroke. Such effects may be heightened when ephedra is combined with caffeine, as in certain weight-loss programs.
Asian or Panax ginseng and Siberian ginseng may also work to decrease fatigue, although studies provide conflicting results, the researchers write.
The bottom line with herbal stimulants is that "caffeine and Panax ginseng ... are both relatively safe and mild preparations in comparison with other conventional and herbal stimulants," Gyllenhaal and colleagues say. They add that further research is needed to determine whether they might be useful as an addition to conventional treatments for people with sleep disorders.
As for herbal sedatives, there is some evidence that valerian and kava may be effective in helping people get to sleep more quickly and sleep more soundly with few side effects. And the researchers note that German chamomile, lavender, hops, lemon balm, and passionflower are reputed to be mild sedatives, but need much more study.
The bottom line is still "buyer beware," Gilbert L. Ross, MD, medical director of the American Council on Science and Health in New York, tells WebMD.
"These substances have not been proven to be safe or effective for any condition. You never know what you are getting or how much of it you are getting, because they are not regulated," Ross says.
"Should people be taking potentially mood-altering drugs on their own? Probably not," he says, "but most sedatives and stimulants will not have any particularly harmful effects."
Still, "I would advise patients not to treat what could potentially be a serious medical problem without first discussing it with a doctor," he says. "Anyone who takes any supplement should specifically tell their health-care provider that they are doing so. Many doctors are unaware that patients take such substances and may prescribe a medication that will interact adversely."
Kenneth Dardick, MD, a family practitioner in Storrs, Conn., and an assistant clinical professor of medicine at the University of Connecticut in Farmington, agrees.
"These are not innocuous substances and they do have biologic activity," says Dardick, who sees many patients with sleep problems. Some can interact with prescription medications to cause bleeding, or increase or decrease the effectiveness of other drugs, he tells WebMD.
And there's a catch-22 that can make this problem worse, he says.
"On one hand, people are reluctant to tell their doctors about the herbs and dietary supplements that they take, and on the other hand, doctors don't know enough about these substances to ask their patients about them," Dardick says.
Although the researchers did not look at supplements of the hormone melatonin, there is some evidence that it may be effective as a sedative and in treating jet lag, Dardick says.
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