One woman woke up with a paintbrush in her hand, having painted her front door in her sleep. People have set fire to their kitchens while trying to cook, cursed their bosses on the phone and crashed their cars into trees – all in a sleeping-pill-induced haze and with no memory afterward.
A flurry of such cases prompted the Food and Drug Administration last year to require that Ambien, Lunesta and other ”sedative-hypnotic” drugs carry strong warnings. But that scarcely damped enthusiasm. U.S. sleep-aid prescriptions grew 10 percent last year, according to IMS Health, thanks in part to generic Ambien.
Now, an analysis of adverse-event reports filed with the World Health Organization suggests that some side effects of this generation of sleep medication, which made their debut in the 1990s, may be nearly as problematic as the older generation, including Halcion, which was banned in some countries.
Through March 2007, the WHO’s international drug-monitoring center received 867 reports from 24 countries of people encountering amnesia, often coupled with confusion, agitation and other behavior disturbances, while taking the newer sleeping aids, called nonbenzodiazepines (NBZs). That compares with 1,032 such reports with the older class of benzodiazepines (BZs), even though they have been on the market for decades longer.
”The older pills are much more likely to cause daytime sedation, addiction and withdrawal symptoms,” says P. Murali Doraiswamy, chief of biological psychiatry at Duke University Medical School and the lead author of the study, presented Monday at the American Psychiatric Association conference in Washington. But, he says, the reports of amnesia and erratic behavior appear to be similar with both kinds of drugs. ”We still don’t have a good handle on how common these events are – some people may be particularly vulnerable,” he says.
A spokeswoman for Sanofi-Aventis, which makes Ambien, the leading brand-name NBZ, says the company cannot comment since it hadn’t seen the report. She adds that somnambulism occurred in fewer than 1 in 1,000 patients in clinical trials, and wasn’t necessarily caused by the medication.
Doctors aren’t certain what prompts some people to eat, walk, make phone calls or get behind the wheel in their sleep. But some speculate that sleep drugs may act on brain circuits unevenly, leaving the parts that govern automatic behaviors running while shutting down the centers of judgment.
”It’s like the parents are away and now the little kids can do whatever they want to,” says Dr. Doraiswamy. As with most dreams, the events aren’t stored in the brain’s memory circuits, hence the amnesia.
Psychiatrist Carlos Schenck at the Minnesota Regional Sleep Disorders Center has studied some 40 cases of Sleep-Related Eating Disorder, and found that it’s more common in women than men, and often accompanies a mood disorder. Some patients have consumed inedibles like buttered cigarettes and woken up gasping for air with their mouths full of peanut butter, a sleep-eating favorite.
Experts all recommend trying nondrug means to combat insomnia – such as exercise, stress reduction and avoiding caffeine. But if you must resort to pills, there are ways to minimize the risks:
Get into bed immediately. Sleeping pills can work in 10 or 15 minutes. Never take more than the maximum dose. Never mix sleeping pills with alcohol. And never take them if you’re planning to drive.
”We’ve had some cases where people are leaving a party and they’re afraid they’re going to have insomnia, so they take one before they get in the car,” says Mark Mahowald, medical director of the Minnesota sleep center. He also cautions against taking a sleep aid if you’re the sole caregiver for a child or are expecting a phone call. In fact, a ringing phone may trigger a sleepwalking event, so unplug it if possible.
Stash your car keys in an unusual spot, suggests William C. Head, an Atlanta attorney who has defended sleeping-pill users who went on unplanned drives.