Washington: People taking pills for a good night's rest could be facing a 4.6 times higher death risk and also significant increase in cancer cases, report said.

These findings by Scripps Health Clinic Research cast a shadow over a growing segment of the pharma industry that expanded by 23 percent in the US from 2006 to 2010 and generated about $2 billion in annual sales.

The study included 10,531 sleeping pill users who were prescribed drugs for an average of 2.5 years and 23,674 control participants who were not prescribed the drugs. "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 ail-ments," said study author Daniel F. Kripke, from Scripps Health's Viterbi Family Sleep Centre, San Diego, the journal BMJ Open reports.

The research is the first to show that eight of the most commonly used hypnotic (sleep inducing) drugs were tied with increased hazards of mortality and cancer, including the popularly prescribed medications zolpidem (brand name Ambien) and temazepam (Restoril), Kripke said, according to a Scripps statement. "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, of the Jackson Hole Centre for Preventive Medicine in Jackson, Wyoming.

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.