People are relying on sleeping pills more than ever to get a good night's rest, but a new study by Scripps Clinic researchers links the medications to a 4.6 times higher risk of death and a significant increase in cancer cases among regular pill users.
The results, published today by the open-access online journal BMJ Open, cast a shadow over a growing segment of the pharmaceutical industry that expanded by 23 percent in the United States from 2006 to 2010 and generated about $2 billion in annual sales.
"What our study shows is that sleeping pills are hazardous to your health and might cause death by contributing to the occurrence of cancer, heart disease and other ailments," said author Daniel F. Kripke, M.D., of the Viterbi Family Sleep Center in San Diego.
The research is the first to show that eight of the most commonly used hypnotic drugs were associated with increased hazards of mortality and cancer, including the popularly prescribed medications zolpidem (known by the brand name Ambien) and temazepam (also known as Restoril), Dr. Kripke said. Those drugs had been thought to be safer than older hypnotics because of their shorter duration of action.
Study participants who took sleeping pills were matched with control patients of similar ages, gender and health who received no hypnotics in order to eliminate the possibility that other factors led to the results.
"We tried every practical strategy to make these associations go away, thinking that they could be due to use by people with more health problems, but no matter what we did the associations with higher mortality held," said co-author Robert D. Langer, M.D., M.P.H., of the Jackson Hole Center for Preventive Medicine in Jackson, Wyoming.
Even among patients who were prescribed 1 to 18 sleeping pills per year, the risk of death was 3.6 times higher than among similar participants who did not take the medications. The study looked at patients aged 18 years and older, and found the increased risk in all age groups.
Rates of new cancers were 35 percent higher among patients who were prescribed at least 132 hypnotic doses a year as compared with those who did not take the drugs.
Using data stored in an electronic medical record that has been in place for more than a decade, the researchers obtained information on almost 40,000 patients cared for by a large integrated health system in the northeastern United States.
The study included 10,531 sleeping pill users who were prescribed the medications for an average of 2.5 years and 23,674 control participants who were not prescribed the drugs. Information came from outpatient clinic visits conducted between Jan. 1, 2002, and Sept. 30, 2006.
"It is important to note that our results are based on observational data, so even though we did everything we could to ensure their validity, it's still possible that other factors explain the associations," said co-author Lawrence E. Kline, D.O., who is medical director of the Viterbi Family Sleep Center. "We hope our work will spur additional research in this area using information from other populations."
Funding for the study came from the Scripps Health Foundation and other philanthropic sources.
The BMJ Open report should prompt physicians to consider alternatives to hypnotic medications, Dr. Kline said.
Clinicians at the Viterbi Family Sleep Center focus on cognitive therapy that teaches patients to better understand the nature of sleep. For example, some people suffering from insomnia might require less than the eight hours of sleep commonly recommended for each night.
Patients also can benefit from practicing good sleeping habits and relaxation, as well as taking advantage of the body's natural clock, which is driven by the rising and setting of the sun, Dr. Kline said. "Understanding how to use the circadian rhythm is a very powerful tool that doesn't require a prescription," he said.
When insomnia results from emotional problems such as depression, doctors should treat the psychological disorder rather than prescribe sleeping pills that could prove to be harmful, Dr. Kripke said.
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