A drug designed to help people with a particular sleep disorder to stay awake could soon be licensed to perk up sleepy shift workers and others affected by drowsiness. The prospect is stirring up a debate about the dangers of popping a pill to counter a sleep-deprived lifestyle.

Provigil, as the drug is known in the US and Britain, is approved for treating the daytime sleepiness associated with the rare condition called narcolepsy, which makes people fall asleep involuntarily. But last week, the drug’s manufacturer, Cephalon of West Chester, Pennsylvania, announced results from a clinical trial of 209 shift workers that showed it helps those with “shift work sleep disorder” – excessive sleepiness caused by odd working hours.