The Food and Drug Administration has issued a new warning about popular sleep drugs -- after studies show they don't leave your system as quickly as previously thought.
New data from driving simulations and blood tests show sleep drugs like Ambien or Ambien CR can still be active the morning after use, and driving could be impaired.
Women appear to be particularly affected because they metabolize the drug slower than men.
Experts are recommending the dose be cut in half for women -- and men should consider using a lower dose.
They say this will ensure less of the drug is present in the blood in the morning.
FDA officials say patients should not change the dose on their own -- rather they should talk to their doctor first.