Does Oxybutynin Cause Dementia? The Answer Varies by Drug

Long term oxybutynin use is associated with higher dementia odds in adults 55 and older. That is an association, not proof the drug causes it. And the signal did not show up for every bladder medication: in a large 2024 study, the authors found no significant increase for five others, including darifenacin and trospium.

That last part is the one that changes what you might ask your doctor.

This article is for informational purposes only and does not constitute medical advice. Consult your doctor or pharmacist for advice specific to your medications.

Why this question keeps coming up

Overactive bladder is common after 55, and oxybutynin (sold as Ditropan) has been treating it since its initial US approval in 1975. More than a million people in the US were prescribed it in 2024, so when research connects it to memory problems, the news travels fast.

The concern is real, but it varies by drug. Oxybutynin belongs to a group called anticholinergics, which block acetylcholine, a chemical messenger your body uses in two very different places. In your bladder it tells the muscle to squeeze. In your brain it helps with memory and learning.

A drug that reaches both places calms your bladder and dampens brain signaling at once. A drug that only reaches your bladder does not. That difference might partly explain what the research found.

What the studies found, drug by drug

The main analysis here is a 2024 study in BMJ Medicine that looked at 170,742 people with dementia and 804,385 matched people without it, using English primary care records. Instead of lumping all bladder drugs together, it reported each one separately.

An odds ratio of 1.28 means the odds were about 28 percent higher in that group, not that 28 percent of people taking it will develop dementia. Across all anticholinergic bladder drugs combined, the figure was 1.18. Mirabegron is in the table because people ask about it, but its number needs the explanation below before it means anything.

This pattern is not new. A 2019 study in JAMA Internal Medicine covering 58,769 dementia cases found bladder antimuscarinics among the two strongest signals of any drug class it examined, at an odds ratio of 1.65 for the heaviest users.

Here is the twist. That same study found no significant increase for antihistamines, though the authors say people not taking their prescribed doses might explain that. The class that got flagged was the bladder one, not the allergy one. That does not clear your nighttime antihistamine, but in this study the bladder drugs drew the stronger signal.

Two that came out better, and the reason why

Darifenacin and trospium are built differently, and the study authors say that might partly explain their results.

Your brain is wrapped in a filter called the blood brain barrier. Some molecules slip through it easily. Others cannot.

Trospium is what chemists call a quaternary amine. Large, water loving and permanently charged, it does not readily cross the barrier. A 2010 study in mice found almost 200-fold higher brain levels for oxybutynin than for trospium at equal doses. In older patients, a 2011 paper in World Journal of Urology reports trospium was "assay undetectable in the cerebrospinal fluid."

Darifenacin takes a different route. Your body has several acetylcholine receptor types. The M3 type runs bladder squeezing. The M1 type sits in the brain and matters for memory. Darifenacin targets M3 while mostly leaving M1 alone. A review in Clinical Interventions in Aging describes darifenacin and solifenacin as "M3-selective receptor antagonists which potentially may be more bladder-specific with reduced tendency for anticholinergic side effects," and says darifenacin's sparing of M1 is "of particular importance for older patients who may be more susceptible to cognitive impairment and central nervous system effects."

Oxybutynin does neither. It crosses the barrier, and it blocks M1 along with M3.

So for these two, the chemistry and the study results point the same way.

One caution: "no significant increase found" is not the same as "proven safe." Few people in the study took some of these drugs, so the authors cannot rule out a risk.

Why mirabegron (Myrbetriq) shows up in the dementia data

People often ask whether mirabegron (Myrbetriq) is the safe alternative. It is a fair question, because mirabegron is not an anticholinergic at all. According to its FDA prescribing information, it is a beta-3 adrenergic agonist that relaxes the bladder muscle through a completely separate pathway.

But the same 2024 study showed higher dementia odds for mirabegron too: 1.27 and 1.62 at the two middle levels of use, though not at the lowest or highest. Taken alone, that looks alarming.

The study authors offer an explanation. They found that "86.2% of individuals prescribed mirabegron (1574 of 1826 patients) had previously used anticholinergic drugs for an overactive bladder." In other words, most mirabegron users had taken an anticholinergic bladder drug first. The authors say the raised number might reflect that history rather than mirabegron itself.

If you see mirabegron listed as a dementia risk somewhere, check whether the source mentions the 86 percent.

Why studies disagree with each other

You may find studies that saw no link for oxybutynin. They are not making it up.

A 2022 Canadian study compared each drug with mirabegron in the year before diagnosis. It reported "No effect was seen with oxybutynin or trospium," while solifenacin, darifenacin, tolterodine and fesoterodine showed higher odds. Both it and the 2024 study say protopathic bias likely explains the oxybutynin result.

Early dementia can cause bladder problems before anyone recognizes the dementia, so the medication gets prescribed because brain changes had already started. Sort the data one way and the drug looks like the cause. Sort it another way and it looks like an early symptom.

Researchers disagree about how much of the signal is which. A 2025 umbrella review in Molecular Psychiatry rated the evidence from three anticholinergic meta-analyses as moderate certainty, not high. It advised "avoidance of anticholinergic drugs in cognitive impairment, with assessment of anticholinergic burden and consideration of alternatives during routine clinical contacts."

Moderate certainty is worth acting on. It is not worth panicking over.

What the label already says

You do not have to settle the dementia debate to find something useful. Oxybutynin's own FDA label states that the drug "is associated with anticholinergic central nervous system (CNS) effects," listing "hallucinations, agitation, confusion and somnolence."

The label also tells prescribers to use caution in people who already have dementia and take cholinesterase inhibitors, because of the risk of worsening symptoms, and to watch for these effects especially in the first few months or after a dose increase.

That guidance does not depend on how the dementia debate resolves.

The 2023 American Geriatrics Society Beers Criteria, a widely used guide to prescribing for older adults, also flags bladder antimuscarinics and recommends reviewing a person's total anticholinergic load at medication reviews.

What to do with this

Do not stop taking your medication because of an article. Overactive bladder itself is linked to falls: a 2018 systematic review in Advances in Therapy found that between 18.9 and 50 percent of people with it had at least one fall, depending on the study. That decision belongs to you and your prescriber together.

What this research supports is a conversation. Three things worth raising:

1. Which bladder drug am I on, and does it reach the brain? The table above is a starting point, not a verdict on your situation.
2. What else am I taking that is anticholinergic? This part is easy to miss. Earlier studies added up every strong anticholinergic a person was prescribed, not just one pill. Some allergy medications, sleep aids, older antidepressants, and drugs like hydroxyzine all count toward the same total.
3. Have I noticed anything? New confusion, word finding trouble, or unusual drowsiness are worth reporting, especially if they started within a few months of a new prescription or dose change.

Bring an accurate list. It is easy to leave things off, especially the over the counter items that never felt like real medication.

How Pillo helps

The burden idea only works if you know the total, and totals are hard to hold in your head when you are managing several medications across different times of day.

Pillo keeps every medication in one list, including the over the counter ones people forget to mention, so you can hand your doctor something accurate instead of rebuilding it from memory in the exam room. Its alarms keep going until you acknowledge them, and each dose you log goes into your history. If you are not sure whether you already took something, that record answers it.

Looking after a parent or partner? Pillo lets you track their medications as a separate dependent inside your own app, with their own schedule, and the reminder lands on your phone. Up to two dependents are free.

Download Pillo on Google Play

A consistent daily routine makes changes easier to notice, and our medication spacing guide covers fitting a new schedule around what you already take.

FAQ

What overactive bladder medication does not cause dementia?

In the 2024 BMJ Medicine analysis, the authors found no significant increase in dementia odds for darifenacin, fesoterodine, flavoxate, propiverine and trospium (trospium was higher at one middle level of use), while oxybutynin, tolterodine and solifenacin showed increases. That is not the same as proven safe. Which drug suits a person depends on their other conditions, what else they take, and how well it actually controls symptoms, so this is a prescriber decision rather than a ranking.

Does oxybutynin cause memory loss?

Oxybutynin's FDA label lists confusion and drowsiness among its known central nervous system effects, and memory impairment among problems reported after it went on sale. Large observational studies also link long term cumulative use to higher dementia odds, though that is an association across populations rather than a guaranteed outcome for any one person. If your memory feels different since starting it, that is worth telling your doctor or pharmacist.

Is oxybutynin memory loss reversible?

These are two different questions. The confusion and drowsiness listed on the label are recognized drug effects, and the label tells prescribers to consider a dose reduction or stopping the drug if they show up. A 2015 study notes the general view that this kind of confusion reverses once the drug is stopped, but adds that several researchers have reported possible lasting problems such as mild cognitive impairment or dementia. That longer term risk is a separate question the research does not answer for individuals, and either way this is not something to test by stopping on your own.

Does Myrbetriq cause dementia?

Mirabegron is not an anticholinergic; it works through beta-3 receptors. Its label lists postmarketing reports of confusion and hallucinations but says a cause has not been established. It did show higher dementia odds at two middle levels of use in the 2024 study, but the authors reported that 86.2 percent of mirabegron users had previously taken anticholinergic drugs, which they say might explain the number.

What counts as long term use?

The 2024 study added up daily doses over time, and the odds climbed with the total. For oxybutynin, the odds ratio was 1.04 below about three months of doses, 1.14 up to a year, and 1.31 and 1.28 beyond a year. Even the lowest total still showed a signal, just a smaller one. Earlier studies went further and added every strong anticholinergic prescription into one running total, which is why a full medication list matters more than any single prescription does.

Should I stop taking oxybutynin if I am worried about dementia?

No, not on your own. Overactive bladder itself is linked to falls, so make that call with your prescriber. The useful move is to book a medication review and ask specifically about your total anticholinergic load, since several of these studies measured exactly that.

What else counts toward anticholinergic burden?

More than you might expect. Older antidepressants, first-generation antihistamines used for allergies or sleep, some muscle relaxants, certain Parkinson's drugs, and antipsychotics all carry anticholinergic activity, and over the counter products count the same as prescriptions. Your pharmacist can total it up from a complete list, which is why bringing one matters.

Sources

• Iyen B, Coupland C, Bell BG, et al. Risk of dementia associated with anticholinergic drugs for overactive bladder in adults aged ≥55 years. BMJ Medicine, 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11580265/ (doi:10.1136/bmjmed-2023-000799)
• Coupland CAC, et al. Anticholinergic Drug Exposure and the Risk of Dementia. JAMA Internal Medicine, 2019. https://pmc.ncbi.nlm.nih.gov/articles/PMC6593623/
• Matta R, Gomes T, Juurlink D, et al. Receipt of Overactive Bladder Drugs and Incident Dementia: A Population-based Case-control Study. European Urology Focus, 2022. https://pubmed.ncbi.nlm.nih.gov/34742663/ (doi:10.1016/j.euf.2021.10.009)
• Gray SL, et al. Cumulative Use of Strong Anticholinergics and Incident Dementia: A Prospective Cohort Study. JAMA Internal Medicine, 2015. https://pmc.ncbi.nlm.nih.gov/articles/PMC4358759/
• Belessiotis-Richards C, et al. Systemic medications and dementia risk: a systematic umbrella review. Molecular Psychiatry, 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12532590/ (doi:10.1038/s41380-025-03129-3)
• Chughtai B, Levin R, De E. Choice of antimuscarinic agents for overactive bladder in the older patient: focus on darifenacin. Clinical Interventions in Aging, 2008. https://pmc.ncbi.nlm.nih.gov/articles/PMC2682382/
• Kranz J, Petzinger E, Geyer J. Brain penetration of the OAB drug trospium chloride is not increased in aged mice. World Journal of Urology, 2011. https://pmc.ncbi.nlm.nih.gov/articles/PMC3557395/
• Geyer J, Gavrilova O, Schwantes U. Differences in the Brain Penetration of the Anticholinergic Drugs Trospium Chloride and Oxybutynin. UroToday International Journal, 2010. https://www.urotoday.com/volume-3-2010/34099-differences-in-the-brain-penetration-of-the-anticholinergic-drugs-trospium-chloride-and-oxybutynin-2227015.html (doi:10.3834/uij.1944-5784.2010.02.12)
• Oxybutynin chloride extended-release tablets, FDA prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ec4fd95f-16dc-4acf-b560-b67b7aaef08b
• Mirabegron extended-release tablets, FDA prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=d22d3d12-8466-46db-bc19-d13e87c6115c&audience=consumer
• Szabo SM, Gooch KL, Walker DR, et al. The Association Between Overactive Bladder and Falls and Fractures: A Systematic Review. Advances in Therapy, 2018. https://pmc.ncbi.nlm.nih.gov/articles/PMC6223978/ (doi:10.1007/s12325-018-0796-8)
• American Geriatrics Society 2023 updated AGS Beers Criteria. https://pubmed.ncbi.nlm.nih.gov/37139824/
• Kane SP. Oxybutynin: Drug Usage Statistics, United States, 2024. ClinCalc DrugStats Database (Medical Expenditure Panel Survey data). https://clincalc.com/DrugStats/Drugs/Oxybutynin

This article provides general information about medication management and is not a substitute for professional medical advice.