Anticholinergic medications — a class of drugs that act on the neurochemical acetylcholine — are linked to an increased rate of emergency department visits and hospital stays in the United States, according to a new study published in the journal Pharmacotherapy.
These medications are frequently prescribed or purchased over the counter for chronic conditions, such as depression, anxiety, pain, allergy, incontinence, or sleep problems. These drugs are used by as many as half of older adults, and it is quite common for an older person to be taking two or more anticholinergic medications regularly.
The study, conducted by researchers at Indiana University (IU) Center for Aging Research, IU Center for Health Innovation, and Implementation Science and Regenstrief Institute, analyzed actual prescription dispensing data of 3,344 individuals from the Regenstrief Medical Record System. They wanted to determine how much anticholinergic medication each person used — known as anticholinergic burden — and how often each individual used healthcare services, including visits to the hospital, emergency department, and ambulance. Prescription dispensing data are considered more reliable than self-reported information.
Anticholinergic burden in this study was defined as the number of days someone was dispensed an anticholinergic medicine multiplied by the strength (mild versus strong) of the anticholinergic load.
Fifty-eight percent of all the participants were African-American, and 71 percent were female. Fewer than 10 percent were cognitively impaired. All were patients served by Eskenazi Health, an academic teaching health care system in Indianapolis.
“Anticholinergics, the medications that block acetylcholine, a nervous system neurotransmitter, have previously been implicated as a potential cause of cognitive impairment, by us and by other researchers,” said IU Center for Aging Research and Regenstrief Institute investigator Noll Campbell, PharmD, who led the new research.
“This is the first study to calculate cumulative anticholinergic burden and determine that as burden increases, so does healthcare utilization in the U.S. — both outpatient and inpatient.”
The findings show that daily use of a drug with a strong anticholinergic effects increased the likelihood of inpatient admission by 33 percent over a year. Sleeping pills, one of the most common medications used by older people, are in this category as are antihistamines, which are available without prescription.
Furthermore, taking a drug with mild anticholinergic effect daily increased the likelihood of inpatient admission by 11 percent over a year. Many drugs used to treat heart failure and hypertension fall into the mild group, such as diuretics.
The IU Center for Aging Research has studied patient safety harms from anticholinergic medications in diverse populations for over a decade.
In 2013, the IU Center for Aging Research investigators reported that continuously taking strong anticholinergics for as few as 60 days led to memory problems and other indicators of mild cognitive impairment. Taking multiple drugs with weaker anticholinergic effects, such as many common over-the-counter digestive aids, had a negative impact on cognition in only 90 days.
“Individuals taking anticholinergics should talk with their doctors or pharmacists about possible alternatives,” Campbell said. “This new study provides stronger motivation to design and conduct de-prescribing studies to determine safe ways to take individuals off anticholinergic medications in the interests of preserving brain health and decreasing healthcare utilization rates and their potential costs.”