By Sam Baker - 01/10/13 07:43 PM EST
The agency also encouraged doctors to consider writing prescriptions for the lower dose for all patients.
“Patients who must drive in the morning or perform some other activity requiring full alertness should talk to their healthcare professional about whether their sleep medicine is appropriate," the FDA's Ellis Unger said in a statement.
The FDA said recent studies have shown the sleep aids remain in the bloodstream the next morning, in quantities large enough to impair driving and similar tasks. That increases the risk of car accidents.