Common Drugs & Memory Loss

Several types of common over-the-counter drugs can cause cognitive impairment. People with a genetic predisposition to Alzheimer’s disease face a 250% increased risk of cognitive impairment from these drugs.

New research published in the medical journal from the American Academy of Neurology highlights several common medications that can cause memory loss and cognitive impairment. These types of medications, called anticholinergic drugs, are taken for allergies, common colds, stomach discomfort, and motion sickness.

This table shows the generic and brand names for common anticholinergic drugs:

Common Anticholinergic Drugs That Can Cause Memory Loss

Generic NameBrand Name(s)
ChlorpheniramineAlka-Seltzer Plus Cold & Cough Liquid Gels
DimenhydrinateDraminate, Dramamine, Gravol
DiphenhydramineBenadryl, Sominex, Tylenol PM, Advil PM, Aleve PM, others
RantidineZantac, Deprezine

The study involved 688 people with an average age of 74 who had no problems with thinking and memory skills at the start of the study. The participants reported if they were taking any anticholinergic drugs within three months of the start of the study at least once a week for more than six months.

The study found that people with biomarkers for Alzheimer’s disease in their cerebrospinal fluid who were taking anticholinergic drugs were four times more likely to later develop mild cognitive impairment than people who were not taking the drugs and did not have the biomarkers.

Similarly, people who had genetic risk factors for Alzheimer’s disease and took anticholinergic drugs were about 2.5 times as likely to later develop mild cognitive impairment than people without the genetic risk factors and who were not taking the drugs.

People who take anticholinergic medications are encouraged to discuss options with their doctors or pharmacists before making changes to their medications, since some of these medications may cause adverse effects if stopped suddenly.