Rx That Put a Wrench in the Works

Anticholinergic medications may affect memory and mental faculties through long term use

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Several medications that help with common ailments could contain chemicals that get in the way of memory function. Communicating about these risks with a healthcare provider may help improve safety.

A recent study looked at the mental functioning of a group of older adults in relation to the medications they had been taking in the previous year.

The results of the study showed that many prescription and over-the-counter medications may contain a substance that can affect memory and thinking in older adults after two to three months of continuous use.

"Tell your doctor about all long-term OTC use."

Noll Campbell, PharmD, and Malaz Boustani, MD, from the Center for Aging Research at Indiana University, worked with a team of fellow scientists to investigate memory problems associated with the use of medications that block the neurotransmitter acetylcholine.  

Acetylcholine blockers, called anticholinergics, are used in both prescription and over-the-counter medications for a variety of conditions, including chronic obstructive pulmonary disease (COPD), heart disease, high blood pressure, insomnia, bladder control, depression and allergies. Certain painkillers and steroids also contain anticholinergics.

Previous studies have shown that long-term use of anticholinergics can interfere with memory function and organized thinking.

For this study, 3,690 older adults were evaluated with the Community Screening Instrument for Dementia (CSI-D). The researchers also looked at all of the prescription and over-the-counter medications each of the participants had taken in the past year.

The researchers diagnosed 562 of the participants with some level of cognitive impairment, such as trouble with thinking, memory and processing information. A total of 277 of those participants did not want to continue with the diagnostic assessment and dropped out of the study.

After the dropouts, among those completing the full assessment, there remained 129 people who had been diagnosed with dementia, 93 who had been diagnosed with mild cognitive impairment and 63 who had been diagnosed as normal.

The researchers used information from 27 previous studies on the mental impact from certain anticholinergics as they evaluated each participant’s medication records. Different medications use different amounts of anticholinergics. Not all medications that contain anticholinergics have the same potential for affecting a person’s mental functioning.

The researchers used the Anticholinergics Cognitive Burden list that compiled information from several studies on how each medication containing anticholinergics can affect the mental faculties of the person taking it.

After making adjustments for other health conditions, the researchers found that the odds of developing mild cognitive impairment were nearly three times higher for older adults that had taken at least three anticholinergics for at least 90 days.

“Our study found an association between anticholinergics burden and the risk of developing cognitive impairment. However, we found that such an association required both high anticholinergic burden and 2 to 3 months of continuous exposure to such a high burden,” said the study authors.

Basically, the authors found an association between taking three mild anticholinergics for 90 days or longer and a 50 percent increase in the chances of developing memory and mental functioning problems.

The researchers found the risk for developing memory and mental functioning problems to increase by roughly 100 percent for older adults taking one or more of the severe anticholinergics for 60 days or longer.

Fortunately, the exposure to anticholinergics did not increase the risk for developing dementia. Although, a limitation to the study, noted by the authors, was the small sample size of older adults taking anticholinergics.

The authors concluded that patients and healthcare providers should communicate about the benefits and harms of taking medications that contain anticholinergics, especially when they involve long-term use.

This study will be published in an upcoming print issue of Alzheimer’s & Dementia.

The National Institutes of Health, the National Institutes of Mental Health, the National Institute on Aging, the Hartford Foundation, the Atlantic Philanthropy and the American Federation of Aging Research provided funding for this project. No conflicts of interest were declared.

Reviewed by: 
Review Date: 
May 10, 2013
Last Updated:
August 13, 2013