Common Drugs Linked to Increased Dementia Risk

A recent report published in JAMA Internal Medicine confirmed a link between dementia risk and commonly used anticholinergic agents, some of which are taken regularly by older adults.

"Older adults should be aware that many medications—including some available without a prescription, such as OTC sleep aids—have strong anticholinergic effects," said first study author Shelly Gray, PharmD, MS, in a press release. “And they should tell their health care providers about all their OTC use.”

The report authors estimated that patients receiving at least 10 mg/day of the tricyclic antidepressant doxepin (Sinequan), 4 mg/day of the first-generation antihistamine chlorpheniramine, or 5 mg/day of the antimuscarinic oxybutynin for more than 3 years had a higher risk of developing dementia, including Alzheimer’s disease. The researchers also suggested that the increased dementia risk associated with those anticholinergic medications could persist even years after patients stop receiving the drugs.

To reduce that risk, Dr. Gray noted that selective serotonin re-uptake inhibitors like citalopram (Celexa) or fluoxitene (Prozac) could replace doxepin for treating depression and a second-generation antihistamine like loratadine (Claritin) could replace chlorpheniramine for treating allergies, while behavioral changes could reduce urinary incontinence for which oxybutynin is commonly prescribed.

"Health care providers should regularly review their older patients' drug regimens—including OTC medications—to look for chances to use fewer anticholinergic medications at lower doses,” Dr. Gray said. “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."

The report tracked 3500 seniors who participated in Adult Changes in Thought, a joint Group Health-University of Washington study funded by the National Institute on Aging. It is the first study to link dementia risk to greater use of anticholinergic medications.