Medical Research: What is the background for this study? What are the main findings?
Dr. Gray: Many medications have anticholinergic effects such as those used to treat overactive bladder, seasonal allergies, and depression. The general view is that anticholinergic-induced cognitive impairment is reversible, however, emerging evidence suggests that these medications may be associated with increased dementia risk. We conducted a prospective population-based cohort study in 3434 older adults to examine whether cumulative anticholinergic medication use is associated with increased risk of incident dementia. Using automated pharmacy data, we found that higher 10-year cumulative dose was associated with increased risk for dementia and Alzheimer disease over an average of 7.3 years of follow-up. In particular, people with the highest use (e.g. taking the equivalent of oxybutynin 5 mg/day or chlorpheniramine 4 mg/day for longer than 3 years) were at greatest risk.
Medical Research: What should clinicians and patients take away from your report?
Dr. Gray: Many older people take medications that have anticholinergic effects. Older adults should be aware that many medications—including some available without a prescription such as over-the-counter sleep aids—have strong anticholinergic effects. They should tell their health care providers about all their over-the-counter use. But of course, no one should stop taking any therapy without consulting their health care provider.
Health care providers should regularly review their older patients’ drug regimens—including over-the-counter medications—to look for chances to use fewer anticholinergic medications at lower doses. If providers need to prescribe a medication with anticholinergic effects because it is the best therapy for their patient, they should use the lowest effective dose, monitor the therapy regularly to ensure it’s working, and stop the therapy if it’s ineffective.
Gray SL, Anderson ML, Dublin S, et al. Cumulative Use of Strong Anticholinergics and Incident Dementia: A Prospective Cohort Study. JAMA Intern Med. Published online January 26, 2015. doi:10.1001/jamainternmed.2014.7663.