“Some drugs commonly used to treat hay fever, insomnia and depression have been linked to a higher risk of Alzheimer’s disease and other forms of dementia, a new study reports. And the longer the medications are taken, the greater the risk.
“The drugs include many popular prescription and over-the-counter medications. They include tricyclic antidepressants like doxepin (Sinequan), antihistamines like chlorpheniramine (Chlor-Trimeton) and diphenhydramine (Benadryl), and bladder control drugs like oxybutynin (Ditropan).
“All of the medications are known to block a brain chemical called acetylcholine, which transmits nerve signals throughout the brain and nervous system. The drugs are known as ‘anticholinergic agents’ and are commonly taken for disorders ranging from allergies and bladder problems to sleep and mood disorders…
“A link between sleep aids and dementia had been reported in earlier studies. And anticholinergic drugs are known to affect cognitive abilities such as attention and working memory in the short term. But this study was larger and more robust, and was the first to show a dose-dependent relationship: taking the drugs for longer periods substantially increased dementia risk. The study is also the first to suggest that adverse effects of using such drugs may persist long after people stop using them, and may not be reversible. The findings appeared in JAMA Internal Medicine, from the American Medical Association…
“The researchers found that over all, long-term use of the drugs significantly increased the risk of developing dementia, including Alzheimer’s disease. The study found, for example, that people taking at least 10 milligrams per day of doxepin (Sinequan, a sleep and depression aid), 4 milligrams a day of diphenhydramine (Benadryl, for allergies or sleep), or 5 milligrams a day of oxybutynin (a bladder control drug) for more than three years would be at increased risk for developing dementia…
“Using such drugs, however, does not mean that you will get Alzheimer’s disease. Surveys suggest that anywhere from 8 percent to 37 percent of Americans take anticholinergic drugs on a regular basis, mostly for such conditions as overactive bladder, seasonal allergies or depression. Most of these people will not develop dementia.
“Still, the results of this study clearly indicate that long-term use of these drugs may be detrimental to the brain. One possibility is that ongoing use of anticholinergic drugs results in damage to the brain that is similar to that seen in Alzheimer’s disease…”
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by William J. Netzer, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Shelly L. Gray, PharmD, MS; Melissa L. Anderson, MS; Sascha Dublin, MD, PhD, et al: “Cumulative Use of Strong Anticholinergic Medications and Incident Dementia: A Prospective Cohort Study.” JAMA Internal Medicine, January 26, 2015
For the complete article, click here.