A new study has tightened the link between dementia and a common class of drugs used to treat a variety of symptoms.
Anticholinergics are a type of medication that blocks the action of acetylcholine, a chemical messenger in the brain that help drive breathing, digestion, urination, and other functions.
They include a roster of drugs for depression (such as Paxil), psychosis (such as Thorazine), Parkinson’s disease (such as Cogentin), and bladder disorders (such as Ditropan).
Published in JAMA Internal Medicine, the University of Nottingham study tracked 284,343 patients age 55 and up between 2004 and 2016. It analyzed total standardized daily doses (TSDDs) of anticholinergic drugs during that time period.
The study found a nearly 50% increase in odds of dementia among people who received more than 1,095 daily doses of these drugs within a 10-year period — equivalent to an older adult taking a strong anticholinergic medication daily for at least three years.
Researchers identified each adult’s anticholinergic exposure and found the most frequently prescribed anticholinergic drugs were antidepressants, drugs to treat vertigo, motion sickness or vomiting and an overactive bladder.
Some other anticholinergic antihistamines and gastrointestinal drugs didn’t correspond to a higher incidence of dementia, the researchers said.
While the study shows a correlation between these specific anticholinergic drugs and increased dementia odds, the researchers cautioned that individuals should not stop taking any medications without talking with their doctor.