September 17, 2014
Longer Benzodiazepine Use Linked With Alzheimer’s
Disease Development

Montreal, Canada—Benzodiazepines used to treat anxiety and sleep issues only should be used for short periods of time, according to a new study that linked long-term use of the medications to increased risk of developing Alzheimer’s disease.

Using data from the Quebec, Canada, health insurance program database (RAMQ), researchers from the University of Montreal Hospital Center in Canada and the University of Bordeaux in France tracked the development of Alzheimer's disease in a sample of elderly residents who had been prescribed benzodiazepines. Their results were published recently by the British Medical Journal (BMJ).

Over a 6-year study period, the researchers identified 1,796 cases of Alzheimer’s disease, comparing the cases to 7,184 healthy people matched for age, sex, and duration of follow-up.

Results indicate that past use of benzodiazepines for 3 months or more was associated with an increased risk of up to 51% for development of Alzheimer’s disease. Furthermore, the strength of association increased with longer exposure and with use of long-acting benzodiazepines rather than short-acting formulations, according to the authors.

The strength of association increased with exposure density (1.32 for 91-180 prescribed daily doses and 1.84 for more than 180 prescribed daily doses. The risk also showed an increase when comparing short-acting drugs (1.43) to long-acting formulations (1.70).

The association held up even when adjusting for symptoms that could indicate the early stages of dementia, such as anxiety, depression, or sleep disorders, the authors note.

According to the report, no association was found for a cumulative dose of fewer than 91 prescribed daily doses.

Benzodiazepines are “indisputably valuable tools for managing anxiety disorders and transient insomnia” the authors write, but warn that treatments “should be of short duration and not exceed three months.”

Pointing out that the nature of the link is still not definitive, the authors suggest that the stronger association seen with long-term exposures “reinforces the suspicion of a possible direct association, even if benzodiazepine use might also be an early marker of a condition associated with an increased risk of dementia. Unwarranted long term use of these drugs should be considered as a public health concern.”

The results are of “major importance for public health, especially considering the prevalence and chronicity of benzodiazepine use in elderly populations and the high and increasing incidence of dementia in developed countries,” according to the report.

Prescribers should “carefully balance the benefits and risks when initiating or renewing a treatment with benzodiazepines and related products in elderly patients,” the authors add.

In an accompanying editorial, Kristine Yaffe, MD, of the University of California at San Francisco and Malaz Boustani, MD, of the Indiana University Center for Aging Research, point out that the American Geriatrics Society updated its list of inappropriate drugs for older adults in 2012 to include benzodiazepines because of their detrimental cognitive side effects.

Still, they note, nearly 50% of older adults continue to use the drugs at some point, potentially adding to the growing prevalence of cognitive impairment among that group.

U.S. Pharmacist Social Connect