Use of anticholinergic medication used in Parkinson’s, vertigo etc daily for three years or more was found to be associated with increased risk of dementia
A new study has found that there was nearly a 50% increased risk of dementia among patients aged 55 years and above, who had used strong anticholinergic medication daily for three years or more.
Anticholinergic drugs help to contract and relax muscles. They work by blocking acetylcholine, a chemical that transmits messages in the nervous system.
Doctors prescribe the drugs to treat a variety of conditions, including chronic obstructive pulmonary disease, bladder conditions, anti-vertigo medications, allergies, gastrointestinal disorders and symptoms of Parkinson’s disease.
These medicines can have short-term side effects, including confusion and memory loss, but it is less certain whether long-term use increases the risk of dementia.
The research, published in the JAMA Internal Medicine journal, looked at the medical records of 58,769 patients with a diagnosis of dementia and 225,574 patients without a diagnosis of dementia, all aged 55 and over and registered with UK GPs contributing data to the QResearch database, between 1 January 2004 and 31 January 2016.
The study findings showed increased risks of dementia for anticholinergic drugs overall and specifically for the anticholinergic antidepressants, antipsychotic drugs, antiparkinsonism drugs, bladder drugs and epilepsy drugs after accounting for other risk factors for dementia
The study findings showed increased risks of dementia for anticholinergic drugs overall and specifically for the anticholinergic antidepressants, antipsychotic drugs, antiparkinsonism drugs, bladder drugs and epilepsy drugs after accounting for other risk factors for dementia.
No increased risks were found for the other types of anticholinergic drug studied such as antihistamines and gastrointestinal drugs.
Professor Tom Dening, Head of the Centre for Dementia at the University of Nottingham and a member of the research study team, said: “This study provides further evidence that doctors should be careful when prescribing certain drugs that have anticholinergic properties.”
Anticholinergic drug exposure was assessed using prescription information over a complete period of 10 years before diagnosis of dementia or the equivalent dates in control patients, and was compared between the two patient groups. Further analysis looked at prescriptions for anticholinergic drugs up to 20 years before diagnosis of dementia.
The most frequently-prescribed types of drugs were antidepressants, anti-vertigo and bladder antimuscarinic drugs – which are used to treat an overactive bladder.
The increased risk associated with these drugs indicates that if the association is causal around 10% of dementia diagnoses could be attributable to anticholinergic drug exposure.
This is a sizeable proportion and is comparable with other modifiable risk factors for dementia, including 5% for midlife hypertension, 3% for diabetes, 14% for later life smoking and 6.5% for physical inactivity.
