Higher cumulative anticholinergic drug use is associated with an increased risk of dementia, according to research published January 26 online ahead of print in JAMA Internal Medicine.
Lead author Shelly Gray, PharmD, MS, and colleagues tracked approximately 3,500 seniors. The most commonly used medications were tricyclic antidepressants (e.g., doxepin), first-generation antihistamines (e.g., chlorpheniramine), and antimuscarinics (e.g., oxybutynin).
The researchers found that people taking at least 10 mg/day of doxepin, 4 mg/day of chlorpheniramine, or 5 mg/day of oxybutynin for more than three years would be at greater risk for developing dementia.
It is the first study to demonstrate a dose response, linking a greater risk for developing dementia to higher use of anticholinergic medications. The findings also suggest that the link between dementia risk and anticholinergic medications may persist and may not be reversible years after people stop taking these drugs.
“Efforts to increase awareness among health care professionals and older adults about this potential medication-related risk are important to minimize anticholinergic use over time,” concluded the researchers.