The Food and Drug Administration (FDA) sent out a strong warning Wednesday about a side effect of popular sleeping pills.

The FDA warned that all sleeping pills, including Ambien and Lunesta, may lead to a condition known as ?sleep driving.? Norwalk doctors say while the side effect is rare, a small number of users have gotten behind the wheel while asleep. Doctors say since people are not fully awake after taking a sleeping pill, they may not react well to certain driving conditions. They add that after the fact, most patients have no memory of driving.

As a result of this side effect, the FDA has ordered the makers of 13 sleep products to strengthen the warnings on their labels. The FDA is also warning about another rare risk of sleeping pills ? a severe allergic reaction that could send a patient into anaphylactic shock.

Related Information: FDA