Seniors face high risk of Alzheimer’s, dementia from anticholinergic drugs

Seniors face high risk of Alzheimer’s, dementia from anticholinergic drugs.

Senior citizens often take anticholinergic drugs, which are commonly prescribed for a wide range of common health conditions

Senior woman looking at drugs in medicine cabinet

Feb. 17, 2015 – There is nothing that strikes fear in the hearts of senior citizens more than the risk of dementia, and Alzheimer’s disease in particular. A recent study found, however, a significantly increased risk for developing dementia, including Alzheimer’s disease from taking commonly used medications with anticholinergic effects, which are taken frequently by older adults, often unknowingly. They even include nonprescription medicines like Benadryl.

But the stern warning about anticholinergics significantly increasing this risk among seniors failed to get the attention it probably deserves.

Senior citizens often take anticholinergic drugs, which are commonly prescribed for a wide range of health conditions. Among the most widely used anticholinergics are antihistamines, including over-the-counter allergy and cold preparations and sleeping aids used regularly by elderly people.

“Older adults should be aware that many medications – including some available without a prescription, such as over-the-counter sleep aids – have strong anticholinergic effects,” said Shelly Gray, PharmD, MS, the first author of the report.

And the greater the use of the drugs, the higher the potential risk, according to the researchers.

“Efforts to increase awareness among health care professionals and older adults about this potential medication-related risk are important to minimize anticholinergic use over time,” they said in their conclusion.

“But of course, no one should stop taking any therapy without consulting their health care provider,” said Dr. Gray, who is a professor, the vice chair of curriculum and instruction, and director of the geriatric pharmacy program at the UW School of Pharmacy. “Health care providers should regularly review their older patients’ drug regimens—including over-the-counter medications—to look for chances to use fewer anticholinergic medications at lower doses.”

JAMA Internal Medicine published the online report, called “Cumulative Use of Strong Anticholinergics and Incident Dementia.” The National Institute on Aging (NIA) supported the research.

Anticholinergics are prescribed for many health conditions in older people, including overactive bladder, depression and even just seasonal allergies. Some are available over the counter and are often used as sleep aids. These medications block a neurotransmitter – acetylcholine – in the brain and body and may cause such side effects as impaired cognition, especially in older people. This side effect was previously thought to be reversible once the person stopped taking the medication.

However, the researchers show that these medications may have a lasting impact.

By analyzing records and data from the NIA-supported Group Health/University of Washington Adult Changes in Thought (ACT) study for drugs prescribed over 10 years to 3,434 seniors age 65 and older, they calculated cumulative exposure to drugs with strong anticholinergic effects.

Prospective population-based cohort study using data from the Adult Changes in Thought study in Group Health, an integrated health care delivery system in Seattle, Washington. We included 3434 participants 65 years or older with no dementia at study entry.

Initial recruitment occurred from 1994 through 1996 and from 2000 through 2003. Beginning in 2004, continuous replacement for deaths occurred. All participants were followed up every 2 years. Data through September 30, 2012, were included in these analyses.

During a mean follow-up of 7.3 years, 797 participants (23.2%) developed dementia. Seventy-nine percent of these (637) developed Alzheimer’s disease).

The analysis showed that 78 percent of ACT participants used anticholinergics at least once in 10 years.

The higher the use of anticholinergics, the higher the risk of dementia, regardless of whether the drugs had been taken recently or years ago.

The findings suggest that physicians treating older people should prescribe alternatives to anticholinergics, when possible, or lower doses of the drugs. More studies are needed to determine to what extent stopping anticholinergics can reduce the risk of developing permanent dementia.

“If providers need to prescribe a medication with anticholinergic effects because it is the best therapy for their patient,” Dr. Gray said. “They should use the lowest effective dose, monitor the therapy regularly to ensure it’s working, and stop the therapy if it’s ineffective.”

Anticholinergic effects happen because some medications block the neurotransmitter called acetylcholine in the brain and body, she explained. That can cause many side effects, including drowsiness, constipation, retaining urine, and dry mouth and eyes.

The study used more rigorous methods, longer follow-up (more than seven years), and better assessment of medication use via pharmacy records (including substantial nonprescription use) to confirm this previously reported link. It is the first study to show a dose response: linking more risk for developing dementia to higher use of anticholinergic medications.

And, it is also the first to suggest that dementia risk linked to anticholinergic medications may persist – and may not be reversible even years after people stop taking these drugs.

“With detailed information on thousands of patients for many years, the ACT study is a living laboratory for exploring risk factors for conditions like dementia,” said Dr. Gray’s coauthor Eric B. Larson, MD, MPH.

“This latest study is a prime example of that work and has important implications for people taking medications—and for those prescribing medications for older patients.” Dr. Larson is the ACT principal investigator, vice president for research at Group Health, and executive director of Group Health Research Institute (GHRI). He is also a clinical professor of medicine at the UW School of Medicine and of health services at the UW School of Public Health.

Some ACT participants agree to have their brains autopsied after they die. That will make it possible to follow up this research by examining whether participants who took anticholinergic medications have more Alzheimer’s-related pathology in their brains compared to nonusers.


University of Washington School of Pharmacy

Founded in 1894, the UW School of Pharmacy is ranked #3 in the world according to Shanghai Jiao Tong University. Follow the School of Pharmacy on Facebook or Twitter.

UW Medicine

UW Medicine is part of the University of Washington. Its system includes Harborview Medical Center, Northwest Hospital & Medical Center, Valley Medical Center, UW Medical Center, UW Neighborhood Clinics, UW Physicians, UW School of Medicine and Airlift Northwest. UW Medicine is affiliated with Seattle Children’s, Fred Hutchinson Cancer Research Center, the Veteran’s Affairs Healthcare System in Seattle, and the Boise VA Medical Center. It shares in the ownership and governance of the Seattle Cancer Care Alliance and Children’s University Medical Group.

Group Health Research Institute

Group Health Research Institute does practical research that helps people stay healthy. The Institute is the research arm of Seattle-based Group Health Cooperative, a consumer-governed, nonprofit health care system. Founded in 1947, Group Health Cooperative coordinates health care and coverage. Group Health Research Institute changed its name from Group Health Center for Health Studies in 2009. The Institute has conducted nonproprietary public-interest research on preventing, diagnosing, and treating major health problems since 1983. Government and private research grants provide its main funding. Follow Group Health research on Facebook, Twitter, or YouTube.

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