By Meera Jagannathan, MarketWatch
Long-term use of some common prescription medications may be linked with heightened risk of dementia.
Researchers found a statistically significant association between dementia and exposure to anticholinergic drugs, especially antidepressants, antipsychotic drugs, anti-Parkinson drugs, anti-epilepsy drugs and bladder antimuscarinics, which are used to treat urinary incontinence, according to the observational study published in the peer-reviewed journal JAMA Internal Medicine .
Anticholinergic drugs work by blocking a neurotransmitter called acetylcholine in the nervous system.
The researchers analyzed data from 2004 to 2016 from 284,343 patients in England aged 55 and up. They found “nearly a 50% increased odds of dementia” linked with exposure to more than 1,095 daily doses of anticholinergics over 10 years, “equivalent to three years’ daily use of a single strong anticholinergic medication at the minimum effective dose recommended for older people.”
Researchers said that antidepressants, antipsychotic drugs, medication to treat Parkinson’s disease, anti-epilepsy drugs and drugs used to treat urinary incontinence, are linked to dementia risk.
“Adverse effects should be considered alongside benefits when these drugs are prescribed, and alternative treatments should be considered where possible,” the authors wrote. “We found greater increases in risk associated with people diagnosed with dementia before the age of 80, which indicates that anticholinergic drugs should be prescribed with caution in middle-aged and older people.”
As usual with studies such as this, the researchers said they weren’t able to establish a causal relationship. If it were to be causal, they noted, that would mean about one in 10 dementia diagnoses could be chalked up to anticholinergic exposure.
The latest study wasn’t the first to draw links between anticholinergic drugs and dementia. Research published in 2015 in the same journal, for example, found that “higher cumulative anticholinergic use is associated with an increased risk for dementia.”
An estimated 5.8 million people in the U.S. — 5.6 million of whom are 65 and older — live with Alzheimer’s disease and related dementia conditions, according to the Centers for Disease Control and Prevention. That prevalence is expected to balloon to 14 million by the year 2060, the CDC says, with Hispanic and African-American populations seeing the greatest increases.
Dementia-related economic costs rose from approximately $279.6 billion in 2000 to $948 billion in 2016, according to global 2017 estimates published in The Lancet that suggested “dementia is a substantial economic burden worldwide.”
One 2013 New England Journal of Medicine study found that the yearly dementia-attributable societal cost per person in 2010 was $41,689 to $56,290, depending on the calculation. Costs included nursing home care, out-of-pocket spending, home care and Medicare.
A separate invited commentary also published this week in JAMA Internal Medicine praised the rigor of the new findings, but cautioned that more evidence was needed.