Anticholinergic Drug Exposure Linked to an Increased Risk of Dementia

The findings of a new study published in JAMA Internal Medicine suggest an association between exposure to several types of strong anticholinergic drugs and an augmented risk of dementia.

Researchers of this nested case-control study recruited 284,343 patients (58,769 dementia patients and 225,574 matched controls, 63% women) 55 years and older (mean age, 82). They used prescription information on a total of 56 drugs with significant anticholinergic properties to calculate drug exposure. The primary exposure of this study was the total standardized daily doses (TSDDs) of any anticholinergics prescribed within the 10-year period prior to date of dementia diagnosis or the equivalent date with respect to the matched control group. Odds ratios (ORs) were used as the study measures, and data were analyzed from May 2016 to June 2018.

A Troubling Correlation

According to the results of the study, the adjusted OR for dementia climbed from 1.06 (95% CI, 1.03 to1.09) in the lowest overall anticholinergic exposure category to 1.49 (95% CI, 1.44 to 1.54) in the highest category, juxtaposed to no anticholinergic drug prescriptions in the 1 to 11 years before the index date. Moreover, the results suggest a significant increase in dementia risk for the anticholinergic antidepressants (adjusted OR [AOR], 1.29; 95% CI, 1.24-1.34), anti-parkinson drugs (AOR, 1.52; 95% CI, 1.16 to 2.00), antipsychotics (AOR, 1.70; 95% CI, 1.53 to 1.90), bladder antimuscarinic drugs (AOR, 1.65; 95% CI, 1.56 to 1.75), and antiepileptic drugs (AOR, 1.39; 95% CI, 1.22-1.57) all for more than 1095 TSDDs. According to the study authors, “these results were similar when exposures were restricted to exposure windows of 3 to 13 years (AOR, 1.46; 95% CI, 1.41to 1.52) and 5 to 20 years (AOR, 1.44; 95% CI, 1.32 to 1.57) before the index date for more than 1095 TSDDs.”

“This study provides further evidence that doctors should be careful when prescribing certain drugs that have anticholinergic properties, said Tom Dening, Head of the Centre for Dementia at the University of Nottingham in a press release. “However, it’s important that patients taking medications of this kind don’t just stop them abruptly as this may be much more harmful. If patients have concerns, then they should discuss them with their doctor to consider the pros and cons of the treatment they are receiving.”

“Our study adds further evidence of the potential risks associated with strong anticholinergic drugs, particularly antidepressants, bladder antimuscarinic drugs, anti-Parkinson drugs and epilepsy drugs,” stated lead researcher Professor Carol Coupland from the University’s Division of Primary Care. “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. These findings also highlight the importance of carrying out regular medication reviews.”

Source: JAMA Internal Medicine, EurekAlert