Raleigh, N.C. — The U.S. Food and Drug Administration is asking several drug manufacturers to strengthen product warning labels for many sleep medications because of risks that people will do things they don’t remember while they’re asleep—including driving.

There have been several stories about people on these medications who end up binge eating, making phone calls, sleep-walking or even sleep-driving. They wake up later with no memory of the event. Perhaps the best-known story is about what happened to U.S. Rep. Michael Kennedy, D-R.I., who drove into a security barrier near the U.S. Capitol in May 2006.

The FDA is concerned with 13 drug products, but two of the most advertised are Lunesta and Ambien.

The regulators want the manufacturers to include stronger language about the potential risks. In addition to what are called "complex sleep-related behaviors, there is also a risk of severe allergic reactions.

The FDA also recommends that the companies conduct clinical studies into these reactions in hopes of getting a better handle on the risks of the various compounds.

Some people use the sleep aids to try to solve sleeping problems rather than address the reasons they are sleeping poorly. The most important sleep problem is stress that comes from problems people have when they are awake—for example, work, marital or financial problems. Counseling may be a better antidote than sleeping pills.

Other causes could be exercise right before bedtime, decongestants before going to bed, too much television viewing late at night—even having a pet sleeping in the bed. All are causes that can be altered.

The FDA would not say exactly how many cases of sleep-driving it had linked to insomnia drugs, but neurology chief Dr. Russell Katz said the agency uncovered more than a dozen reports and is worried that more are going uncounted.

Doctors will begin getting letters this week notifying them of the new warnings. Later this year, all prescription sleeping pills will begin coming with special brochures called "Medication Guides" that spell out the risks for patients in easy-to-understand language.

To lower the risk of a sleep-driving episode, Katz advised patients to never take any prescription insomnia drug along with alcohol or any other sedating drug. Also, don't take higher-than-recommended doses of the pills.

Sleep-driving made headlines last May when Kennedy crashed his car after taking Ambien and a second drug, Phenergan, an anti-nausea pill that also acts as a sedative. Kennedy has said he had no memory of the event, but he pleaded guilty to driving under the influence of prescription drugs and was sentenced to court-ordered drug treatment and a year's probation.