The popular sleep drug Ambien can leave even the healthiest older people groggy and prone to stumbling, falling and confusion when they wake up, U.S. researchers reported on Thursday.

The drug, sold by Sanofi-Aventis under the brand name Ambien and known generically as zolpidem, appears to act broadly in the brain and has a numbing effect for at least half an hour after waking, the researchers reported in the Journal of the American Geriatric Society. Get the full story »