Older Adults Advised to Limit Anticholinergic Medicines

 Older adults should limit how many anticholinergic medicines they take and use the lowest effective dose for the shortest time needed, the Medicines and Healthcare products Regulatory Agency (MHRA) has advised. The advice follows a safety review of bladder anticholinergic drugs, which found that a small increased risk of dementia cannot be ruled out.

The review found that current evidence is not sufficient to confirm that bladder anticholinergics cause dementia. Taking more than one anticholinergic drug raises the risk of side effects, and ageing reduces the body's ability to process medications, the MHRA said.

Anticholinergics block the action of acetylcholine, whose effects include regulating heartbeat, promoting alertness, and managing bladder activity. Overactive bladder and urinary incontinence are common in dementia. An estimated 53% of people with dementia have incontinence, compared with around 13% of those without dementia. Bladder anticholinergics are a first-line treatment option.

Cognitive Effects 

In the brain, acetylcholine is responsible for nerve communication, memory, and learning. Some symptomatic treatments for Alzheimer’s disease work by boosting acetylcholine levels. The MHRA said that common side effects of anticholinergics include short-term memory loss and confusion, especially among older adults. It is less certain if they have longer-term effects on memory and thinking, including whether their use is linked to an increased risk of dementia. 

However, prolonged exposure has been linked to long-term cognitive decline and dementia incidence among both community living cohorts and nursing home residents. It has been unclear whether the increased risk is specific to the anticholinergic action itself, or due to the underlying conditions for which the drugs were prescribed. Several studies have suggested a specific link between bladder anticholinergics, also called bladder antimuscarinics, and the development of dementia.

Robust Association With Dementia Incidence 

For example, a large case-control study published in The BMJ in 2018 found “a robust association between some classes of anticholinergic drugs and future dementia incidence”. 

The adjusted odds ratio for anticholinergics known to impose the highest cognitive burden was 1.11, and involved antidepressants (predominantly amitriptyline, dosulepin, and paroxetine), urological therapeutics (predominantly oxybutynin and tolterodine), and antiparkinson drugs, but not those used in allergies or gastrointestinal conditions. 

Those affected had used the drugs for between 4 and 20 years before being diagnosed, and risk was greater with longer duration of use. The researchers concluded that the association could have been due to a class-specific effect, or to the drugs being used for very early symptoms of dementia.

A similar study from the Universities of Nottingham, Southampton, and Oxford, published in JAMA Internal Medicine in 2019, found an adjusted odds ratio (OR) for dementia that increased from 1.06 in the lowest overall anticholinergic exposure category to 1.49 in the highest, compared with no anticholinergic drug prescriptions, in the 1-11 years before the index date. There were significant increases in dementia risk for anticholinergic antidepressants (OR, 1.29), antiparkinson drugs (OR, 1.52), antipsychotics (OR, 1.70), bladder antimuscarinics (OR, 1.65), and antiepileptics (OR, 1.39). 

Another study published in Age and Ageing in 2025 found that among prospective cohorts in both the UK Biobank and the US All of Us program, higher use of anticholinergic medications was associated with increased risks of both dementia (hazard ratio [HR], 1.06-1.15) and mortality (HR, 1.16-1.23).

Many Memory Service Patients Have Anticholinergic History 

In a retrospective study from Wales presented at the British Geriatrics Society conference in 2025, a history of anticholinergic prescription was present in 65% of those referred to a memory assessment service.

A review of available data was initiated on the recommendation of the Commission on Human Medicines (CHM), which considered that, generally, it had “low confidence” in the studies. The MHRA examined evidence from marketing authorisation holders, including nonclinical and clinical studies, suspected adverse drug reaction reports submitted through the Yellow Card Scheme, and a critical appraisal of observational studies published since the last review in 2017.

Risk Not Ruled Out 

The MHRA's Public Assessment Report concluded that the available evidence was not sufficient to confirm that bladder anticholinergic medicines directly increase the risk of developing dementia; however, the limitations of these studies meant that a small increased risk could not be completely ruled out.

Considering the strengths and limitations of the available data, the CHM concluded that there remained “considerable uncertainty whether the use of bladder anticholinergics directly increases the risk of developing dementia”. 

It therefore recommended that healthcare professionals should aim to limit the number of anticholinergic medicines older people take, and use the lowest dose for the shortest time needed to control their condition.

https://www.medscape.com/viewarticle/older-adults-advised-limit-anticholinergic-medicines-2026a1000pmy