The last big shift in the sleeping-pill market came 12 years ago, when Ambien hit pharmacy shelves in the U.S. The drug is viewed as having fewer side effects than older sleep aids such as Halcion, which left patients feeling groggy in the morning.
Meanwhile, regulars recently demanded more data before approving Neurocrine Biosciences ' (nasdaq: NBIX - news - people ) indiplon sleeping pill, prompting partner Pfizer (nyse: PFE - news - people ) to drop its deal with Neurocrine last week.