Studies show long-term use of over-the-counter cold medicines that contain antihistamines can increase the risk of developing dementia.
These medications can also be dangerous for people who already have dementia.
That's because antihistamines interfere with a chemical in the brain called acetylcholine. That chemical acts as a neurotransmitter that serves a vital role in memory.
Dr. Michael Plopper, chief medical officer for Sharp Behavioral Health Services, said people with dementia are more susceptible to negative effects of medications.
“And in particular the antihistamine medications, and can develop confusional states, short-term memory problems, problems with balance, and other potential side effects," Plopper explained.
Many over-the-counter cold and allergy medicines, including Tylenol PM and Bendryl, contain antihistamines.
Plopper said they should be used sparingly among people with dementia.
"They need to be taken in low dose, they should not be taken routinely, and in all incidences, a person’s physician should be able to review whatever over-the-counter medicines a person is taking," he said.