Commonly used over-the-counter drugs have been linked to dementia in a new study.
A team of researchers assessed pharmacy records, as well as substantial nonprescription use, over the course of seven years to link high doses of anticholinergic medications to an increased chance of dementia.
"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," Shelly Gray, one of the study's aunthors, said in a news release. "And they should tell their health care providers about all their over-the-counter use."
The most commonly used drugs in the study include Sinequan, Chlor-Trimeton, Ditropan and Benedryl.
Although the study found an increased risk of dementia when a patient used these common drugs, Gray warned that no one should stop taking any therapy without consulting their health care provider and that providers should be regularly reviewing older patients' drug regimens 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," Gray said in the release. "They should use the lowest effective dose, monitor the therapy regularly to ensure it's working, and stop the therapy if it's ineffective."
Some of the study participants agreed to have their brains autopsied after they die, which will help the scientists follow up this study by examining whether participants who took anticholinergic medications have more Alzheimer's-related pathology in their brains, as compared to nonusers.
An estimated 35.6 million people in the world are living with dementia. This number is expected to double by 2030 and more than triple by 2050, according to the World Health Organization.
The study was published in the journal JAMA Internal Medicine.