Increased Mortality Rate from Drugs for Insomnia or Anxiety

Last week I blogged about NSAID-users being exposed to an increased risk of stroke.  Now there’s a report of other common medications being associated with an increased likelihood of earlier death (an increased mortality rate).  Drugs to treat anxiety and insomnia in Canada have been studied for this possible effect, and the results reported in the Canadian Journal of Psychiatry.  Twelve years ago an elevated mortality risk was first associated with anti-insomnia drug use, and there has been a similar result from a Swedish study.  Other studies have been inconsistent and controversial.

Over 14,000 people aged 18 to 102 (average, 44 years), who were participating in the National Population Health Survey in Canada, were surveyed every 2 years between 1994 and 2007.  They were asked about their use of tranquilizers (e.g. Valium® or Ativan®) and sleeping pills (e.g. imovane [Zopiclone®], Nytol®, or Sonata®).  During the 12 years’ observation period, the prevalence of use of anxiolytics (minor tranquilizers) was 2.99% to 4.6%, and of hypnotics it was 3.16% to 6.02%.  

Mortality was 15.7% in the participants who said they took anxiolytics or sleeping pills at least once in the month before the questionnaire, vs. 10.5% in those who didn’t take these drugs.  This represents a 3.22-times greater odds of mortality in those taking these meds.   These odds were reduced to 1.36-times greater after adjustments were made for alcohol and tobacco use, physical health and exercise, and the presence or absence of depression. 

Why the increased risk?  There are several possibilities. Benzodiazepines, used as anxiolytics, may decrease reaction times, etc, leading to accidents or falls.  They can also depress the respiratory system, encouraging infections like bronchitis and pneumonia.  But these, certainly, are not the entire story.  For the moment, it’s enough to know that any effective drug has side effects, and that some of them may be delayed, or obscure . . .