A recent scientific study has issued warnings that certain commonly prescribed medications could elevate the risk of dementia. The research indicates that drugs frequently used to treat conditions like bladder issues, Parkinson’s disease and depression may significantly up the chances of developing dementia in the older population.
According to the University of Nottingham’s findings, supported by the National Institute for Health Research (NIHR), those over 55 taking strong anticholinergic drugs daily for an extended period of three years or more showed a nearly 50% higher risk of dementia, particularly vascular dementia. Dr James Pickett, Head of Research at Alzheimer’s Society, commented on the study’s publication: “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.”
He also mentioned a caveat, saying: “A shortcoming of this type of study is that from this information we can’t rule out whether the diseases that cause dementia might have already begun in the brains of people involved before they started taking these drugs.”
Pickett highlighted that current guidelines advise doctors against giving anticholinergic drugs to frail elderly individuals due to their effects on memory and cognition, but suggested that the new evidence should make healthcare providers cautious about prescribing them to all middle-aged and elderly people, as prolonged usage could heighten dementia risk.
Anticholinergic drugs, which help to contract and relax muscles by blocking acetylcholine, a chemical that transmits messages in the nervous system, are commonly prescribed for a range of conditions. These include chronic obstructive pulmonary disease, bladder conditions, allergies, gastrointestinal disorders and symptoms of Parkinson’s disease.
While these medicines can have short-term side effects such as confusion and memory loss, it is less clear whether long-term use increases the risk of dementia. A study led by Professor Carol Coupland from the University’s Division of Primary Care, published in the JAMA Internal Medicine journal, examined the medical records of 58,769 patients with a diagnosis of dementia and 225,574 patients without a diagnosis of dementia.
All were aged 55 and over and registered with UK GPs contributing data to the QResearch database, between 1 January 2004 and 31 January 2016. The research, first reported on in 2019, found increased risks of dementia for anticholinergic drugs overall and specifically for the anticholinergic antidepressants, antipsychotic drugs, antiparkinsons drugs, bladder drugs and epilepsy drugs after accounting for other risk factors for dementia.
The study found no increased risks associated with other types of anticholinergic drugs 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 team, emphasised that this study provides further evidence that doctors should exercise caution when prescribing certain drugs with anticholinergic properties.
However, he warned patients against abruptly stopping these medications as it could be more harmful. He advised patients with concerns to discuss them with their doctor to weigh the pros and cons of their treatment.
The study involved 58,769 dementia patients, with an average age of 82, and 63% were women. Each dementia case was matched to five control patients of the same age, sex, and general practice.
Professor Coupland added: “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.”
“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.”de
