Prescription drugs to combat insomnia are widely used—an estimated 6 to 10 percent of American adults take sedative hypnotics, the class of drugs that make up nearly all sleeping pills today. Concerns about sleeping pills have centered around their potential for overuse and dependency. But, now, experts are raising questions about a more serious health concern.

A study in the online journal BMJ Open has associated hypnotics with a significantly increased risk of death and cancer among adults who use the drugs when compared with nonusers. Popular insomnia drugs tied to the higher rates include Ambien (zolpidem), Lunesta (eszopiclone), Sonata (zaleplon) and Restoril (temazepam).

Comparing users and nonusers

Using health system medical records from a sample population in Pennsylvania, experts tracked more than 10,500 patients who took the drugs over five years. They compared the death and cancer rates of pill users with the rates of more than 23,000 people of similar health who weren't taking any sleeping pills. The sleeping pill group had an average death rate of 6.1 percent compared with the non-pill group whose death rate was 1.2 percent, even after adjusting for lifestyle factors.

The risk was heightened for people who took as few as one to 18 pills during any given year—they had a more than threefold increased risk of death. The more sleeping pills a person took, the higher the risk. Patients who took 132 doses or more a year were five times more likely to die. Moreover, those heavy users were 35 percent more likely than nonusers to develop certain types of cancers, such as lymphomas and lung, colon and prostate cancers.

Yet it's important to note that, although researchers found a link between sleeping pills, death and cancer, they couldn't establisha direct relationship. So, could there be other reasons people who take prescription sleeping pills die prematurely or get cancer? Possibly—the study couldn't account for several confounding factors that might have contributed to higher death and cancer rates.

First, people who take hypnotics tend to be less healthy than the average person to begin with. Although researchers made adjustments for lifestyle habits and health conditions in the study, the medical records they used didn't include information about patients' psychiatric states, so they couldn't account for the possible influence of mental conditions on death rates.

Second, even though the medical records reported that doctors prescribed sleeping pills, there's no guarantee that the patients actually filled the prescriptions or took the drugs.

A word of warning

Despite these shortcomings, the study—which isn't the first to find a link between hypnotic use and increased mortality—underscores the need to weigh the benefits of sleeping pills against their potential risks. Sleeping pills can be helpful as a step in treating persistent insomnia, but they are rarely recommended as a long-term solution. Doctors already know that patients generally shouldn't use hypnotics for an extended period and that the drugs can become habit forming.

Side effects can be serious: confusion, memory impairment, daytime drowsiness, impaired motor skills and loss of coordination and balance. The drugs have also been known to cause people to get up at night, and in a half-awakened state, engage in activities like eating, making phone calls and driving—without recalling doing so in the morning.

If you use sleeping pills, don't stop taking them without consulting your doctor. You'll need to safely reduce the dose so you don't experience a rebound effect that will cause worsened sleep for a few nights. Talk with your doctor about alternatives to medication or ask to see a sleep specialist who can help pinpoint the underlying reason for your sleeplessness and recommend treatment.

Source: Prepared by the Editors of The Johns Hopkins Medical Letter: Health After 50

Publication Review By: the Editorial Staff at

Published: 25 Jul 2013

Last Modified: 23 Jan 2015