Study found that anticholinergics, drugs commonly taken for various conditions including insomnia and motion sickness, significantly increases risk of developing long-term cognitive impairment in older African-Americans. The finding complements previous work that confirmed a link between anticholinergics and delirium, according to Dr. Noll Campbell, PharmD, co-author of the study published in Neurology.

Evaluation of 1,652 African-Americans over the age of 70 was conducted by researchers from Indiana University School of Medicine, the Regenstrief Institute and Wishard Health Services. The subject’s cognition, normal when the study began, was monitored over a period of six-years.

"We found that taking one anticholinergic significantly increased an individual's risk of developing mild cognitive impairment and taking two of these drugs doubled this risk,” said Dr. Campbell.

Anticholinergics block acetylcholine, a nervous system neurotransmitter. The drug is found in various medicines under brand names such as Benadryl®, Dramamine®, Excedrin PM®, Nytol®, Sominex®, Tylenol PM®, and Unisom®. More anticholinergic drugs are available by prescription.

“Simply put, we have confirmed that anticholinergics, something as seemingly benign as a medication for inability to get a good night's sleep or for motion sickness, can cause or worsen cognitive impairment, specifically long-term mild cognitive impairment which involves gradual memory loss,” said Malaz Boustani, M.D., IU School of Medicine associate professor of medicine who co-authored the study. He recommends all older adults to talk with their physicians before taking any type of medications.

Future studies will find that the results are generalizable to other races, both Dr. Campbell and Dr. Boustani believe. Whether anticholinergic-induced cognitive impairment can be reversed will be examined in studies that follow.