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A report has not found sufficient evidence to say that bladder anticholinergic medicines increase the risk of dementia; however, a small increased risk cannot be ruled out, it said.
In a public assessment report — entitled ‘Bladder anticholinergics: review of risk of dementia‘ — published on 27 July 2026, the Medicines and Healthcare products Regulatory Agency (MHRA) said: “The overall findings of the review are that the available evidence is not sufficient to confirm that use of bladder anticholinergic medicines directly increases the risk of developing dementia; however, the limitations of these studies mean that a small increased risk cannot be ruled out completely.”
The report recommended that — in line with clinical guidance — healthcare professionals should aim to limit the number of anticholinergic medicines older people take by using the lowest dose to control a patient’s condition for the shortest length of time.
In the last few years, several studies have considered whether people who take anticholinergic medicines have a higher risk of dementia. Those studies include a large study, published in the BMJ in 2018, the findings of which linked anticholinergic drugs to an increased risk of dementia decades later, and a study published in JAMA Internal Medicine in 2019.
The Commission on Human Medicines (CHM) recommended that the MHRA undertake a review of the available data for bladder anticholinergic medicines to examine whether it raised any new safety concerns or changed current understanding about a possible link between the use of these medicines and the onset of dementia.
The CHM is a non-departmental public body that advises government ministers and the MHRA on the safety, efficacy and quality of medicines. The MHRA presented the data and evidence to the CHM, which it considered at its meeting in September 2025.
Anticholinergic medicines can be prescribed for a range of medical conditions, including controlling bladder function. Common side effects include short-term memory loss and confusion, which older people may be more likely to experience.
Healthcare professionals already know to carefully consider the possible short-term impact on memory when prescribing anticholinergic medicines to older people, the report said.
It also highlighted that taking more than one anticholinergic medicine may increase the risk of side effects, including effects on memory, attention and thinking.
The CHM considered that, generally, the studies “produced findings in which we have low confidence”, with all 17 studies included in the review found to be at serious or critical risk of bias “and consequently their results should be interpreted with caution”.
However, it also took into consideration that any future studies were likely to suffer from similar limitations. The report noted that the data currently available “may be the best data that we will have to inform the need for regulatory action and therefore the findings need to be carefully considered”.
For example, none of the studies were able to adjust for anticholinergic burden that may result from use of over-the-counter products and other covariates, such as lifestyle factors (e.g. BMI, alcohol consumption and smoking status), may not have been fully adjusted for, the report said.
The report highlighted that baseline cognitive impairment was also not adjusted for in the analyses in most of the studies as only two studies included it as a covariate.
Overall, the CHM concluded in the report that while the studies suggested an association between use of bladder anticholinergics and a risk of dementia, owing to the complexities of the data and the limitations of the studies, there remained “considerable uncertainty” as to whether there was a causal link.
The data did not allow a conclusion that there were clear differences in risk of dementia for the individual bladder anticholinergic drug substances, it added.
Ian Maidment, professor in clinical pharmacy at Aston University, told The Pharmaceutical Journal on 29 July 2026: “It’s a very complex area. This is an extensive review of the literature [and] adverse events reports, plus experts were consulted.
“If you’ve got dementia, or if you’re at a pre-dementia stage, these drugs are likely to worsen the symptoms. The issue is, do they increase the risk of dementia? And that is really difficult to say… People want to know, and I don’t think we’re going to get the answer, certainly in the short-to-medium term.”
He also suggested the report was still a useful reference source if a patient asks their pharmacist for advice.
“It’s a conversation between the patient and the prescriber. Does the benefit from the drug outweigh the potential unknown risk?” Maidment said.
