There's new data that shows levels of the drug called Zolpidem (Zolpidem is sold under several names including Ambien) may be high enough to impair alertness in some patients the morning after using it.
The manufacturer is being asked to lower the recommended doses.
Women appear to be more susceptible to the risk as they eliminate Zolpidem from their bodies slower than men do.
Zolpidem is also marketed under several names: Ambien, Ambien CR, Edluar and Zolpimist.
In the meantime patients should speak to their doctors.