WASHINGTON -- A pill that helps people stay awake may be recommended for shift workers and chronic snorers at a meeting of health advisors set for Thursday.

Cephalon Inc. wants Food and Drug Administration approval to more widely market the drug Provigil, which is currently cleared only for treating narcolepsy, a rare disorder marked by uncontrollable sleep during normal waking hours.

Provigil's growing sales suggest the drug already is being prescribed beyond its approved use as word has spread that it can keep people awake and alert.

But West Chester, Pennsylvania-based Cephalon says Provigil, which it described as having gentler side effects than caffeine, is not intended as a quick fix for sleep-deprived parents or college students cramming for an exam, Reuters reported.

"We're not advocating this as a replacement for sleep ... this is for when excessive sleepiness is a medically disabling symptom of a serious underlying condition," Dr. Paul Blake, Cephalon's senior vice-president of clinical research and regulatory affairs, said in an interview.

Cephalon says it has conducted successful tests of Provigil on patients with narcolepsy, shift workers and people with obstructive sleep apnea, a condition that leads to collapse of the upper airway and frequent waking.

An FDA advisory panel will further consider whether to recommend that the agency approve Cephalon's request, which would permit the company to market Provigil for the additional uses. The FDA usually follows the advice of its advisory panels.

FDA staff told the advisers they had not completed their review of Cephalon's application. "However, we have reviewed the sponsor's description of the controlled trial data and are in general agreement with the results of their analyses," an FDA official said in a memo for the advisors posted Wednesday on the Internet at http://www.fda.gov/ohrms/dockets/ac/03/briefing/39 79b2.htm

FDA staff also asked whether the studies would permit an assumption that Provigil would be effective in combating jet lag and other forms of excessive sleepiness.

The drug's sales have risen rapidly. Provigil sales rose 40 percent in the second quarter of 2003 to $69.5 million, from the prior-year period. Blake acknowledged that most prescriptions likely are not written for narcolepsy.

Provigil targets a part of the brain that controls sleep and waking, but researchers do not know exactly how it works, Blake said.

Studies showed Provigil, known generically as modafinil, improved alertness with mild to moderate side effects including headaches and nausea, according to Cephalon. Provigil is gentler than caffeine, which can make people shaky and jittery, Blake said.

"There's no buzz or high that you get ... It makes people feel relatively normal, alert and wakeful, perhaps even surprising themselves how normal they feel," he said.