BETA
This is a BETA experience. You may opt-out by clicking here

More From Forbes

Edit Story

Study Finds A Common Class Of Drugs May Increase Dementia Risk, But There’s Some Good News As Well

Following
This article is more than 4 years old.

A recent study found evidence linking a class of popular drugs called anticholinergics to increased risk of developing dementia. These are common over-the-counter and prescription medications, and this is a troubling finding (and it’s not the first), but the research also conceals a piece of good news that we’ll circle back to after unpacking a few of the details.

What this study found

Anticholinergics include a wide range of popular medications, including certain drugs for allergies, gastrointestinal disorders, bladder control, epilepsy, Parkinson’s disease, as well as anticholinergic antidepressants and antipsychotics. The drugs work by blocking the action of a neurotransmitter called acetylcholine that plays a role in causing involuntary muscle movements throughout the body, from the lungs to the digestive system.

The study found a nearly 50% increased risk of dementia among patients who had used anticholinergics for at least three years. Researchers analyzed data collected between 2004 and 2016 from more than 225,000 patients without a dementia diagnosis, and nearly 59,000 with a dementia diagnosis. The patients were all over 55 years old, and many of them had been on the medications for longer than three years.

How these findings compare to those from previous studies

Previous research has found similar associations between this class of drugs and dementia, including a 2015 study of more than 3,400 patients who used the drugs over a 10-year period. Patients in that study were 65 and older, and links were found to more general forms of dementia and Alzheimer’s disease.

A 2018 study also found a significant dementia link with some types of anticholinergics during a nine-year period for patients older than 65. 

Who seems at greatest risk

The latest study found the greatest risk for patients who had been diagnosed with dementia before the age of 80, which suggests that middle age could be an especially perilous period for taking these drugs.

“The risks of this type of medication should be carefully considered by healthcare professionals alongside the benefits when the drugs are prescribed and alternative treatments should be considered where possible, such as other types of antidepressants or alternative types of treatment for bladder conditions,” said study co-author Professor Carol Coupland from the University of Nottingham, in a press statement.

And the good news...

The good news is that two types of popular anticholinergics were not implicated in this study: antihistamines and gastrointestinal medications.

Some previous research found a dementia link with first-generation antihistamines (brands including Benadryl, Chlor-Trimeton and Dimetane), which are taken by millions of people globally. Popular anticholinergic gastrointestinal medications include the brands Imodium and Phenergan, among others, that are also used widely worldwide.

That the latest study didn’t find the same dementia link with these medications doesn’t necessarily mean they're risk free, but there’s no new evidence from this study to raise more concern.

All of the studies (from 2015, 2018 and the latest) found correlations between anticholinergics and dementia, not conclusive, clinical evidence. None should be construed as proving the drugs cause dementia. They did, however, find significant associations in the data, and taken together those associations shouldn’t be ignored.

The latest study was published in JAMA Internal Medicine.

Follow me on TwitterCheck out my website or some of my other work here