A study from Western University, Lawson Health Research Institute and ICES provides further evidence of a link between a common class of medications called anticholinergics and the onset of dementia.
Anticholinergic medications are those that act on the body’s cholinergic receptors, and are used to treat a range of conditions from allergies and nausea to overactive bladder and psychiatric disorders.
Using ICES data for more than 60,000 Ontarians, Dr. Blayne Welk looked at a specific group of patients with a condition known as overactive bladder. This condition, which affects one in ten Canadians, can be treated with two different classes of medication – anticholinergic medication, and another medication class known as beta-3 agonists. Both medications are effective for treating overactive bladder.
The results of the study showed an increase in the number of new cases of dementia for patients being treated with an anticholinergic medication compared to those being treated with beta-3 agonists. While the overall risk for dementia was low, the rate was 20 per cent higher for patients treated with an anticholinergic medication. During the study, 2.3 per cent of people developed dementia if they used an anticholinergic, as compared to 1.6 per cent of people who used a beta-3 agonist medication.
“The unique thing about this study is that with overactive bladder there is a new medication that isn’t an anticholinergic, so it allowed us to do a very good comparison between two groups of patients that all have the same condition at the start of the study,” said Dr. Welk, an Associate Professor at the Schulich School of Medicine & Dentistry at Western and Scientist at Lawson Health Research Institute. “We were able to confirm with more certainty that there is an increased risk of dementia with the use of anticholinergic medication.”
Dr. Welk hopes this study will help to further emphasize the cognitive risks associated with this class of drugs, and to encourage physicians to consider alternative medications or appropriate deprescribing where possible.
“The hope is to draw attention from the medical community to consider the cognitive side-effects when prescribing anticholinergic medications,” Dr. Welk, who is also an Adjunct Scientist at ICES said. “With overactive bladder, we have an alternate medication choice now that works through a different pathway. If a patient has cognitive dysfunction, it may be appropriate to consider using a non-anticholinergic medication first for the treatment of overactive bladder symptoms.”
