The next time you consider popping a pill when you have trouble nodding off, it might be worth counting sheep instead. A senior psychiatrist at the Scripps Clinic Sleep Center in San Diego, Calif. has found evidence that taking sleeping pills regularly can increase the risk of skin cancer.
Daniel F. Kripke, M.D.’s article, based on a compilation of studies involving sleeping pills and cancer, has just been published in the Journal of Sleep Research. It appears with an editorial authored by Dr. Gary D. Friedman, an epidemiologist at Stanford University’s School of Medicine and adjunct investigator at the Kaiser Permanente Medical Care Program who has vast experience in investigating the carcinogenic effects of drugs.
The effects of 556 person-years of taking either zaleplon (Sonata), Eszopiclone (Lunesta), ramelteon (Rozerem) and zolpidem (Ambien) were assessed, compared to a control group who took a placebo over 230 person-years. Kripke found eight non-melanoma skin cancers and four tumors of uncertain malignancy in the groups that took sleeping pills compared to none in the placebo groups.
Lab animals given high doses of hypnotic drugs are known to have developed kidney, thyroid and testicular cancers and suffer chromosome damage, which is a sign of carcinogenicity. Although a direct causal link between cancer and sleeping pills has still not been proven, Kripke urges additional studies as well as serious epidemiological investigations, given the fact that sleeping pill use is constantly rising and three new types have been put on the market in addition to Ambien (zolpidem), the most popular brand used in the United States.
“Because the compilation mixes diverse studies of several drugs and the number of cancers observed during controlled hypnotics trials remains small,” Kripke writes, “this preliminary analysis should be viewed as an investigative step, rather than sufficient proof that modern hypnotics cause cancer.”
But both he and Friedman — who congratulated Kripke for raising this important issue even though the reviewer remained somewhat skeptical of a causal link — urge caution and suggest that regulatory bodies and the U.S. National Institutes of Health keep an eye on cancer cases reported by sleeping pill users.
The Journal of Sleep Research is published by Wiley-Blackwell and can be accessed online at http://www.blackwellpublishing.com/jsr
Source: SCRIPPS CLINIC