Symptoms of some drugs may imitate dementia

By all accounts, the woman, in her late 60s, appeared to have severe dementia. She was largely incoherent. Her shortterm memory was terrible. She couldn’t focus on questions that medical professionals asked her.

But Malaz Boustani, a doctor and professor of aging research at Indiana University School of Medicine, suspected something else might be going on. The patient was taking Benadryl for seasonal allergies, another antihistamine for itching, Seroquel (an antipsychotic medication) for mood fluctuations, as well as medications for urinary incontinence and gastrointestinal upset.

To various degrees, each of these drugs blocks an important chemical messenger in the brain, acetylcholine. Boustani thought the cumulative impact might be causing the woman’s cognitive difficulties.

He was right. Over six months, Boustani and a pharmacist took the patient off those medications and substituted alternative treatments. Miraculously, she appeared to recover completely. Her initial score on the MiniMental State Examination had been 11 of 30 - signifying severe dementia - and it shot up to 28, in the normal range.

An estimated 1 in 4 older adults take anticholinergic drugs - a wide-ranging class of medications used to treat allergies, insomnia, leaky bladders, diarrhea, dizziness, motion sickness, asthma, Parkinson’s disease, chronic obstructive pulmonary disease and various psychiatric disorders.

Older adults are highly susceptible to negative responses to these medications. Since 2012, anticholinergics have been featured prominently on the American Geriatrics Society Beers Criteria list of medications that are potentially inappropriate for seniors.

“The drugs that I’m most worried about in my clinic, when I need to think about what might be contributing to older patients’ memory loss or cognitive changes, are the anticholinergics,” said Rosemary Laird, a geriatrician and medical director of the Maturing Minds Clinic at AdventHealth in Winter Park, Fla.

Here’s what older adults should know about these drugs.

Anticholinergic medications target acetylcholine, an important chemical messenger in the parasympathetic nervous system that dilates blood vessels and regulates muscle contractions, bodily secretions and heart rate, among other functions. In the brain, acetylcholine plays a key role in attention, concentration, and memory formation and consolidation.

Some medications have strong anticholinergic properties, others less so. Among prescription medicines with strong effects are antidepressants such as imipramine (brand name Tofranil), antihistamines such as hydroxyzine (Vistaril and Atarax), antipsychotics such as clozapine (Clozaril and FazaClo), antispasmodics such as dicyclomine (Bentyl) and drugs for urinary incontinence such as tolterodine (Detrol).

In addition to prescription medications, many common over-the-counter drugs have anticholinergic properties, including antihistamines such as Benadryl and Chlor-Trimeton and sleep aids such as Tylenol PM, Aleve PM and Nytol.

Common side effects include dizziness, confusion, drowsiness, disorientation, agitation, blurry vision, dry mouth, constipation, difficulty urinating and delirium, a sudden and acute change in consciousness.

Unfortunately, “physicians often attribute anticholinergic symptoms in elderly people to aging or age-related illness rather than the effects of drugs,” according to a research review by physicians at the Medical University of South Carolina and in Britain.

Seniors are more susceptible to adverse effects from these medications for several reasons: Their brains process acetylcholine less efficiently. The medications are more likely to cross the blood-brain barrier. And their bodies take longer to break down these drugs.

In the late 1970s, researchers discovered that deficits in an enzyme that synthesizes acetylcholine were present in the brains of people with Alzheimer’s disease.

“That put geriatricians and neurologists on alert, and the word went out: Don’t put older adults, especially those with cognitive dysfunction, on drugs with acetylcholine-blocking effects,” said Steven DeKosky, a neurologist and deputy director of the McKnight Brain Institute at the University of Florida.

Still, experts thought that the effects of anticholinergics were short-term and that if older patients stopped taking them, “that’s it - everything goes back to normal,” Boustani said.

Concerns mounted in the mid2000s when researchers picked up signals that anticholinergic drugs could have a long-term effect, possibly leading to the death of brain neurons and the accumulation of plaques and tangles associated with neurodegeneration.