A new study provides the strongest evidence that anticholinergic drugs may increase the risk for dementia in older adults.
The drugs implicated are commonly used, estimated to be taken by about 20% of the older adult population for many conditions. They include popular antihistamines sold over the counter as sleep aids, such as diphenhydramine (Benadryl, McNeil-PPC Inc), or for allergy relief, such as chlorpheniramine; oxybutynin and tolterodine for overactive bladder; and the tricyclic antidepressants, such as doxepin or amitriptyline, even when used at low doses for migraine prevention or neuropathic pain.
The study, published online in JAMA Internal Medicine, was conducted by a team led by Shelly Gray, PharmD, University of Washington, Seattle.
“We found an obvious dose-response relationship between anticholinergic drug use and risk of developing dementia: the higher the usage, the greater the risk,” Dr Gray commented to Medscape Medical News.