Overactive Bladder Medication and Dementia Risk

Millions of people take medication for overactive bladder, and many of them don’t know about a growing body of research linking some of these drugs to cognitive decline. Over the past five years, studies from the UK, Canada, France, and Japan have all pointed in the same direction: certain overactive bladder medications may raise the risk of dementia, particularly with long-term use.

This doesn’t mean everyone on bladder medication should panic. The story is more specific than the headlines suggest, and some OAB drugs appear to carry no extra cognitive risk at all. Here’s what the research actually shows, which drugs are concerning, and what you can do about it.

How Anticholinergic Bladder Drugs Affect the Brain

Most traditional overactive bladder medications belong to a class called anticholinergics. They work by blocking acetylcholine, a chemical messenger that triggers bladder muscle contractions. Less acetylcholine signaling means fewer involuntary bladder spasms and less urgency.

The problem is that acetylcholine isn’t just active in the bladder. It plays a central role in memory, attention, and learning within the brain. When a drug blocks acetylcholine throughout the body, the brain’s cognitive processes can suffer too.

Some anticholinergics cross the blood-brain barrier more easily than others. Oxybutynin, for example, is lipophilic (fat-soluble) and readily enters the brain. Trospium, on the other hand, is a larger molecule that has difficulty crossing that barrier 1. This difference in brain penetration helps explain why not all anticholinergic bladder drugs carry the same dementia risk.

What the Largest Studies Found

The 2024 BMJ Study (England)

The most significant study to date analyzed data from 170,742 patients with dementia and 804,385 matched controls without dementia, drawn from English medical records between 2006 and 2022 1.

The results were striking:

Any anticholinergic OAB drug use was associated with an 18% increased odds of dementia (adjusted OR 1.18, 95% CI 1.16-1.20)
Oxybutynin showed the highest risk: 31% increased odds with moderate use (366-1095 daily doses) and 28% with heavy use
Solifenacin increased risk by 18-29% depending on duration
Tolterodine increased risk by 25-27%
Trospium, darifenacin, and fesoterodine showed no significant increase

The risk was slightly higher in men (22% increase) than women (16% increase). The study looked at drug use 3-16 years before dementia diagnosis, which helps rule out the possibility that patients were prescribed these drugs because of early, undiagnosed cognitive symptoms.

The 2024 Japanese LIFE Study

Japan’s Longevity Improvement & Fair Evidence Study followed nearly 1.5 million people aged 65 and older, comparing dementia rates between anticholinergic and beta-3 agonist users 2.

Patients on anticholinergic medications had a 22% higher risk of developing dementia compared to those taking beta-3 agonists (adjusted hazard ratio 1.22, 95% CI 1.15-1.30). This study was valuable because it directly compared the two drug classes in the same population of over 38,000 OAB patients.

One detail worth noting: among adults under 65, the difference in dementia rates between the two drug classes was not statistically significant. The increased risk was concentrated in older adults.

The Canadian Study (Ontario, 2021)

A Canadian case-control study examined 11,392 dementia cases and 29,881 controls, all over age 66 3.

Risk varied by specific drug:

Solifenacin: 24-34% increased odds
Darifenacin: 30-49% increased odds
Tolterodine: 21% increased odds
Fesoterodine: 39% increased odds

Interestingly, this study found no increased risk with oxybutynin, which contradicts the BMJ findings. The researchers noted that differences in prescribing patterns between countries may account for this discrepancy. The comparison drug was mirabegron, a beta-3 agonist, which showed no dementia association.

Which Overactive Bladder Medications Are Concerning?

Not all bladder medications work the same way. Here’s where the evidence stands for specific drugs:

Higher concern (anticholinergics with consistent evidence of cognitive risk):

Oxybutynin (Ditropan) — strongest evidence of risk, crosses the blood-brain barrier easily
Solifenacin (Vesicare) — consistent risk signal across multiple studies
Tolterodine (Detrol) — moderate risk, one of the most widely prescribed OAB drugs

Lower concern (anticholinergics with less evidence of risk):

Trospium (Sanctura) — does not easily cross the blood-brain barrier
Darifenacin (Enablex) — mixed results across studies
Fesoterodine (Toviaz) — mixed results

No cognitive concern (non-anticholinergic):

Mirabegron (Myrbetriq) — beta-3 agonist, different mechanism entirely
Vibegron (Gemtesa) — beta-3 agonist, different mechanism entirely

Beta-3 agonists relax the bladder muscle through a pathway that has nothing to do with acetylcholine. They don’t interfere with brain chemistry related to memory, which is why they serve as the comparison group in these dementia studies.

Duration and Dose Matter

A consistent pattern across all the major studies: short-term use appears relatively safe, while long-term use carries more risk.

The 2024 BMJ study showed that dementia risk increased with cumulative dose 1. Taking oxybutynin for a few weeks to manage a flare-up is different from taking it daily for three years. The Society for Urodynamics, Female Pelvic Medicine, and Urogenital Reconstruction (SUFU) has stated that use under four weeks is “likely safe in most individuals,” while chronic use beyond three months warrants caution 4.

This dose-response relationship strengthens the case that the association is real. Random statistical noise doesn’t typically get stronger with increased exposure.

Who Faces the Most Risk?

Age is the biggest factor. The studies consistently show:

Adults over 65 face the clearest risk, especially those already showing mild cognitive changes
Adults under 55 had lower absolute risk in most analyses, though fewer studies specifically examined younger populations
Men may face slightly higher risk than women (22% vs 16% increase in the BMJ data)
People with other dementia risk factors (family history, cardiovascular disease, diabetes) may be especially vulnerable

The Japanese LIFE study’s finding that under-65 adults showed no significant difference between drug classes is reassuring for younger patients 2. But more research specifically focused on younger populations is needed before drawing firm conclusions.

What to Do If You’re Currently Taking These Medications

Don’t stop your medication abruptly. Suddenly stopping bladder medication can cause a return of urinary urgency and frequent urination that may be worse than before treatment. Any changes should happen in consultation with your doctor.

Here’s a practical approach:

Check your medication list. Look for oxybutynin, solifenacin, tolterodine, or other anticholinergics. If you’re not sure what you’re taking, ask your pharmacist.
Ask about switching. If you’re on an anticholinergic, ask your prescriber about trying a beta-3 agonist like mirabegron or vibegron. These treat overactive bladder without affecting acetylcholine.
Try non-drug options. Bladder training and pelvic floor exercises are recommended as first-line treatments by most clinical guidelines. Many people find they can reduce or stop medication with these approaches. Yoga and magnesium supplementation may also help some people manage symptoms.
Review your total anticholinergic load. Bladder medication might not be the only anticholinergic you’re taking. Certain antihistamines, antidepressants, and other common drugs also have anticholinergic effects, and the risk may be cumulative.

Important Limitations of This Research

These studies show an association between anticholinergic OAB drugs and dementia, not definitive proof of causation. People with early, undiagnosed cognitive decline might be more likely to develop bladder symptoms, creating what researchers call reverse causation. The BMJ study tried to address this by looking at drug use 3-16 years before diagnosis, but this possibility can’t be entirely eliminated.

The absolute risk increase is modest. An 18-31% increase in relative odds sounds alarming, but the baseline risk of dementia varies by age and other factors. For a 70-year-old woman, the absolute annual risk might shift from roughly 1.5% to 1.8%. That’s meaningful across a population of millions, but it doesn’t mean any individual will develop dementia from their bladder medication.

That said, when safer alternatives exist and work just as well for most patients, the evidence argues for choosing them.

When to See a Doctor

Talk to your doctor or pharmacist if:

You’ve been taking an anticholinergic bladder medication for more than three months
You’ve noticed memory problems, confusion, or difficulty concentrating since starting your medication
You’re over 65 and want to review your medication safety
You want to explore non-drug treatments for overactive bladder symptoms

If you’re dealing with both bladder symptoms and cognitive concerns, mention both to your doctor. The overlap between overactive bladder in older adults and cognitive health is an active area of research, and your doctor needs the full picture to help you.

Frequently Asked Questions

Can overactive bladder medication cause dementia?

Some overactive bladder medications, specifically anticholinergic drugs like oxybutynin, solifenacin, and tolterodine, have been linked to a higher risk of dementia in large population studies. The risk appears to increase with longer use and higher doses. Newer beta-3 agonists like mirabegron and vibegron do not carry this risk.

Is oxybutynin safe for long-term use?

Long-term oxybutynin use is associated with a 28-31% increased risk of dementia in adults over 55, according to a 2024 BMJ study of over 170,000 patients 1. Short-term use under four weeks appears safer. If you’ve been taking oxybutynin for months or years, talk to your doctor about switching to a safer alternative.

What is the safest medication for overactive bladder?

Beta-3 agonists such as mirabegron (Myrbetriq) and vibegron (Gemtesa) are currently considered the safest prescription medications for overactive bladder regarding cognitive side effects. They work through a completely different mechanism and do not block acetylcholine, the brain chemical involved in memory.

Should I stop taking my bladder medication?

Do not stop any medication without talking to your doctor first. If you’re concerned about dementia risk, schedule a conversation with your prescriber. They can evaluate your individual risk factors, discuss alternatives, or adjust your dose. Stopping suddenly may cause a return of urinary symptoms.

Do beta-3 agonists cause dementia?

No evidence links beta-3 agonists like mirabegron or vibegron to increased dementia risk. A 2024 Japanese study of nearly 1.5 million people found that patients using beta-3 agonists had significantly lower dementia rates compared to those on anticholinergic bladder medications 2.

Summary

The evidence linking certain overactive bladder medications to dementia risk has grown stronger over the past several years. Multiple large studies from different countries consistently show that anticholinergic drugs, particularly oxybutynin, solifenacin, and tolterodine, are associated with a modest but real increase in dementia risk with long-term use in adults over 65.

Safer alternatives exist. Beta-3 agonists like mirabegron and vibegron treat overactive bladder symptoms without affecting brain chemistry, and non-drug approaches like bladder training and pelvic floor exercises remain effective first-line treatments.

If you’re currently taking an anticholinergic bladder drug, this isn’t a reason to panic. But it is a reason to have a conversation with your doctor about whether a safer option might work for you.

References

Welk B, et al. Risk of dementia associated with anticholinergic drugs for overactive bladder in adults aged ≥55 years: nested case-control study. BMJ. 2024;387:e080757. PubMed
Okui N, et al. Risks of dementia associated with anticholinergic medication compared to beta-3 agonist among older patients with overactive bladder in Japan: the LIFE Study. Int J Geriatr Psychiatry. 2025;40(1):e70036. PubMed
Welk B, et al. Receipt of overactive bladder drugs and incident dementia: a population-based case-control study. J Urol. 2022;207(4):896-902. PubMed
UCSF MedConnection. New guidance for reducing medication-related dementia risk in patients with overactive bladder. Link