Allergy medications found to cause mild cognitive impairment including memory loss in older populations

Researchers from Indiana University School of Medicine, the Regenstrief Institute and Wishard Health Services conducted a six-year observational study on 1,652 Indianapolis area African-Americans over the age of 70 who had normal cognitive function when the study began. The researchers tracked both the over-the-counter and the prescription medicines that they took over the period as well as monitoring their cognitive function.

The drugs monitored included brands such as Benadryl®, Dramamine®, Excedrin PM®, Nytol®, Sominex®, Tylenol PM®, and Unisom® and prescription only drugs, such as Paxil®, Detrol®, Demerol® and Elavil®. All are anticholinergics, blocking acetylcholine, a nervous system neurotransmitter, and are used as sleep aids and to relieve bladder leakage problems as well as to relieve allergic reactions.

They 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.

However, the researchers were encouraged by the fact that taking anticholinergics is linked with mild cognitive impairment, involving memory loss but not with Alzheimer's Disease and that anticholinergic-induced cognitive impairment may be reversible. Finding a link between anticholinergics and long term mild cognitive impairment complements the team’s previous work which confirmed a link between anticholinergics and delirium, which is a sudden onset cognitive impairment.

Although this study looked at only African-Americans, researchers believe future studies will find that the results are generalisable to other races.

Courtesy of

First published in July 2010

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