A review of several studies involving sleeping pills and cancer by a senior psychiatrist at the Scripps Clinic Sleep Center in San Diego has revealed that regularly taking sleeping pills can increase the risk of skin cancer. The findings of Daniel F. Kripke, MD, are published in the Journal of Sleep Research.

Overall, Kripke compared the effects of 556 person-years of taking one of four commonly prescribed sleeping pills (Sonata, Lunesta, Rozerem, and Ambien) to a control group of 230 person-years of taking a placebo. The comparison found eight non-melanoma skin cancers and four tumors of uncertain malignancy in the groups that took sleeping pills, while finding none in the placebo groups.

Published with the findings is an editorial by Gary D. Friedman, MD, an epidemiologist at Stanford University’s School of Medicine who has much experience investigating the carcinogenic effects of drugs.

Although a direct causal link has not been proven between sleeping pills and skin cancer, both Friedman and Kripke urge caution. The researchers also suggest that regulatory bodies and the National Institutes of Health make a note of cancer cases reported by sleeping pill users.

“Because the compilation mixes diverse studies of several drugs and the number of cancers observed during controlled hypnotics trials remains small, this preliminary analysis should be viewed as an investigative step, rather than sufficient proof that modern hypnotics cause cancer,” Kripke says.

Read the abstract here.