The drug modafinil, marketed in the United States under the brand name Provigil is prescribed for chronic fatigue associated with sleep disorders. Some medical experts believe drugs like Provigil may one day help the whole nation solve its sleep problem.

Sleep expert Mark Mahowald says most Americans don't get a good night's sleep. "The majority of adults in our country - and really all industrialized countries - are chronically and probably significantly sleep deprived," he says.

Dr. Mahowald is a professor of neurology at the University of Minnesota. "Sleep is a biological imperative. Everybody is given a kind of genetically determined sleep requirement. The average is seven and a half hours, but the range [in reality] is four hours on the short end to ten hours on the long end," he says. "If we get less sleep than our brains are programmed to require, then there will be some degree of impairment of performance - particularly in sustained attention."

The consequences? U-S businesses lose an estimated $18 billion a year due to sleep-related loss of productivity. And the worst-case scenario? "A lot of the major disasters of the world - the [1989] Exxon Valdez [oil spill, environmental disaster off the coast of Alaska], [the 1984] Bhopal, [India, gas leak killing 4,000], the explosion of the [Space Shuttle] Challenger [in 1986], - all those were felt to be due to errors in judgement by people who were sleep-deprived. So there is a cost and a price we pay for working in a less-than-fully-rested condition," he says.

David Plotz of Washington, DC., says that on a typical day, he's never fully rested. Rising early in the morning to care for his two small boys, he drives to his downtown business office and his hectic, 10 hour job. Late at night, he has trouble winding down. David Plotz says he's often so tired, he falls asleep at his desk at work.

Mr. Plotz tried the prescription drug Provigil, and the results were amazing. "My colleagues [at work] noticed I talked a lot. I was working so efficiently and with such pleasure, doing things I normally don't like to do."

Mr. Plotz says when he went home "I was in very high spirits until about midnight. My wife was falling asleep, and I was still chattering with her. I had an 18-hour day, which was productive as any two days I normally have. I felt great the whole day, without particularly feeling anything unnatural was happening to me. It was like being my best self for a whole day. I was just loving the drug."

Millions of others have also found a lot to like about the drug with the chemical name modafinil. James Walsh is the director of sleep medicine at St. John's and St. Luke's Hospitals in Saint Louis, Missouri. He says modafinil works like caffeine - without causing jitters. "Modafinil is similar to other stimulants, like caffeine and amphetamines, things like that. One of the unique characteristics is that, although it has the same alerting potential as some of those other drugs, it doesn't have the cardiovascular negative impact of caffeine and amphetamines, where your heart rate goes up and blood pressure goes up - things of that nature," he says.

And Mark Mahowald at the University of Minnesota says Provigil is also non-addictive. "There's absolutely no known or little abuse or addiction-potential. It counteracts sleepiness due to whatever cause. It's a very effective stimulant medication," he says.

It's not yet known how many Americans take Provigil. Many haven't even heard of it because the U.S. Food and Drug Administration, or FDA, has recommended only limited use. The FDA advises doctors prescribe it for the neurological disorder narcolepsy, for shift-work drowsiness, and also the respiratory illness sleep apnea.

But many doctors are ignoring the FDA guidelines and writing prescriptions for so-called "off-label" use of the drug - for a whole range of conditions that cause fatigue: like depression, Parkinson's Disease, the neurological disease multiple sclerosis - even general sleepiness.

While "off-label" prescriptions are not covered by health insurance, many patients are willing to pay for Provigil. Ninety percent of last year's sales were "off-label," according to the maker of the drug.

"I was amazed at the percentage of prescriptions that are "off label" primarily because of the cost. You write a prescription for ten tablets and that's $80 dollars," says Dr. Mahowald.

Sales of Provigil exceeded $300 million last year - and are expected to reach $400 million this year. Experts say the growing use of Provigil raises ethical questions and medical concerns.

The U.S. military has experimented with Provigil. In volunteer studies simulating combat conditions, troops have stayed awake for a week. James Walsh, the Saint Louis sleep-medicine expert, says that's not wise - at least for average Americans. "We might be able to forestall sleep or even replace it for a short period of time in terms of maintaining alertness without sleep," he says. "But what we don't know, and this is very important, is there a negative, physiological impact of going without sleep for a [long] period of time?"

Even though he's amazed by what modafinil can do, Dr. Mark Mahowald admits it's double-edged sword. "[Say] you're an across-the-road [long-distance] trucker, driving more hours than he should. He's falling asleep driving a sixteen-wheeler. You know he's not going to get sleep just because you recommend he do so - because it [would reduce] his income. So you've got two choices: you can say, 'I'm not going to give you the stimulant medication because it's wrong to do this - because you're depriving yourself of sleep on purpose.' Or, 'I'm going to give you the medication so you don't kill yourself because you might fall sleep while driving and kill yourself and others.' I mean, it's a very sticky issue."

And the issue is becoming more troublesome. Cephalon, the company that makes Provigil, is coming out with a new drug called "Nuvigil", which Cephalon says will keep people awake and alert even longer. So debate over these drugs is likely to intensify.