Commonly-prescribed drugs liked to 50% increased risk of dementia
Commonly used anticholinergic drugs may raise dementia risk by about 50 per cent, research into medicines for bladder problems and depression suggests.
Regular daily use of strong anticholinergic medicines for three years or more was linked to a markedly higher dementia risk in older adults.
Anticholinergic drugs block acetylcholine, a chemical messenger in the nervous system that helps muscles contract and relax.
They are used for chronic obstructive pulmonary disease (COPD), bladder problems, allergies, gastrointestinal disorders and Parkinson’s symptoms.
Professor Carol Coupland, who led the study from the University of Nottingham’s division of primary care, said: “Our study adds further evidence of the potential risks associated with strong anticholinergic drugs, particularly antidepressants, bladder antimuscarinic drugs, anti-Parkinson drugs and epilepsy drugs.”
Specialists at the University of Nottingham, backed by the National Institute for Health Research, analysed the records of 58,769 people with dementia and 225,574 without.
All were aged 55 or over and registered with UK GPs contributing to the QResearch database between 1 January 2004 and 31 January 2016.
While these medicines can cause short-term confusion and memory problems, the team examined whether long-term use raises the chance of dementia.
Findings first reported in 2019 linked anticholinergic drugs overall with increased dementia risk.
The association was strongest for anticholinergic antidepressants, antipsychotics, anti-Parkinson’s drugs, bladder drugs and epilepsy drugs, even after other risk factors were taken into account.
No increased risks were seen for antihistamines or gastrointestinal drugs.
Coupland said: “The risks of this type of medication should be carefully considered by healthcare professionals alongside the benefits when the drugs are prescribed and alternative treatments should be considered where possible, such as other types of antidepressants or alternative types of treatment for bladder conditions.
“These findings also highlight the importance of carrying out regular medication reviews.
“We found a greater risk for people diagnosed with dementia before the age of 80 which indicates that anticholinergic drugs should be prescribed with caution in middle-aged people as well as in older people.”
A separate US study led by Shelley Gray, a pharmacist at the University of Washington’s School of Pharmacy, tracked nearly 3,500 men and women aged 65 and older for an average of seven years.
During that time, 800 of the volunteers developed dementia.
People who used anticholinergic drugs were more likely to have developed dementia than those who did not use them, and dementia risk increased along with the cumulative dose.
Professor Tom Dening from the Centre for Dementia said: “This study provides further evidence that doctors should be careful when prescribing certain drugs that have anticholinergic properties.
“However, it’s important that patients taking medications of this kind don’t just stop them abruptly as this may be much more harmful. If patients have concerns, then they should discuss them with their doctor to consider the pros and cons of the treatment they are receiving.”
The Alzheimer’s Society added: “Our own researchers have already shown a strong link between anticholinergic drugs and risk of dementia.
“This study builds on this information, showing that long-term, high-dose use increases risk of some dementias, particularly vascular dementia.”
