If you’ve been dealing with frequent urination, leaking, or trouble emptying your bladder, the problem might not be your bladder at all. It might be sitting in your medicine cabinet.

A surprising number of everyday medications can cause bladder problems. A 2025 analysis of the FDA’s adverse event database identified 19 medications as independent risk factors for urinary incontinence alone, with neuropsychiatric drugs accounting for the majority 1. And that’s just incontinence. When you include retention, urgency, and frequency, the list grows considerably.

I went through the research on each major medication class so you don’t have to. Here’s what I found.

1. Antihistamines (Allergy Medications)

This one catches people off guard. You take a Benadryl for allergies and end up unable to urinate properly. First-generation antihistamines like diphenhydramine (Benadryl) and doxylamine (found in NyQuil) have strong anticholinergic effects. That means they interfere with the nerve signals that tell your bladder muscle to contract.

One study found a 28.4% incontinence rate among women using certain antihistamines, the highest of any medication class examined 2. On the retention side, case reports show symptoms developing within 48 hours to a week of starting these medications 3.

What to do instead: Second-generation antihistamines like cetirizine (Zyrtec), loratadine (Claritin), and fexofenadine (Allegra) have much lower anticholinergic activity. Loratadine shows less than 2% adverse urinary event rates. If you need allergy relief and have bladder concerns, these are worth discussing with your doctor.

2. Cold and Flu Decongestants

Pseudoephedrine, the active ingredient in Sudafed and many cold medications, directly contracts your bladder neck and urethra. That’s the opposite of what you want when you’re trying to urinate. It stimulates alpha-1A receptors, which increases resistance at the bladder outlet 4.

The risk is age-dependent. Patients 50 and older showed significant increases in urinary symptom scores after taking pseudoephedrine, while younger patients didn’t 4. Pseudoephedrine is formally contraindicated in people with urinary retention and bladder outlet obstruction. Even a 3-year-old has been reported with acute retention from this drug 5.

My take: If you have an enlarged prostate or any history of trouble urinating, avoid pseudoephedrine entirely. Ask your pharmacist about alternatives that don’t affect the urinary tract.

3. Diuretics (Water Pills)

This seems obvious in hindsight but often gets overlooked. Loop diuretics like furosemide (Lasix) increase urine production by design. The problem is they don’t just make you urinate more. They create sudden surges of urine that can overwhelm a bladder that’s already sensitive.

Research shows loop diuretics increase urinary frequency and urgency by 5 to 6 times in elderly patients 6. A study in the American Journal of Hypertension called this “a frequent but often overlooked problem.” If you’re taking a loop diuretic and experiencing overactive bladder symptoms, the medication may be a significant contributor.

Worth noting: Extended-release formulations of loop diuretics (like torsemide ER) reduce peak urine output by about 35% while still controlling blood pressure. Thiazide diuretics are generally less aggressive than loop diuretics. These are conversations to have with your prescribing doctor.

4. Antidepressants (SSRIs and SNRIs)

Antidepressants are an underappreciated source of medication-related bladder problems. SSRIs like sertraline and fluoxetine increase sphincter tone and reduce bladder contractions through their effects on serotonin receptors. The result can be urinary retention or incontinence, depending on the individual 7.

About 15 out of every 1,000 SSRI users per year develop urinary incontinence, with patients over 60 at highest risk 8. Sertraline carries a relative risk of 1.72 compared to other SSRIs. SNRIs tend to cause worse voiding problems than SSRIs.

The paradox: Duloxetine, an SNRI, is actually used to treat stress incontinence in some countries. The same drug class that causes bladder problems in some people provides relief for others.

5. Blood Pressure Medications

Several classes of blood pressure drugs affect the bladder, each in different ways.

Alpha-blockers like doxazosin and prazosin relax smooth muscle, including the urethral sphincter. One study found they increase urinary incontinence risk nearly fivefold in women 9. (Ironically, for men with benign prostatic hyperplasia, alpha-blockers like tamsulosin are prescribed specifically to improve urination.)

Calcium channel blockers like amlodipine are associated with nocturia in men over 40 10.

ACE inhibitors have been linked to stress urinary incontinence 11.

What this means: If you started a new blood pressure medication and noticed bladder changes, they could be connected. Don’t stop your medication on your own, but do mention the timing to your doctor. There are usually alternative drugs that control blood pressure without the urinary side effects.

6. Opioid Pain Medications

Opioids cause bladder problems through multiple pathways: anticholinergic effects, spinal cord mu-receptor binding that suppresses bladder contractions, reduced sensation of fullness, and increased sphincter tone 12. Up to 10% of medication-related urinary retention cases involve opioids, and the effects are present with all opioids including morphine, oxycodone, and fentanyl 13.

People with existing lower urinary tract symptoms are at higher risk of opioid-related bladder problems.

Some good news: Opioid-induced bladder dysfunction can be reversed with naloxone or methylnaltrexone, which don’t affect pain relief 14. If you’re post-surgical and experiencing retention, your medical team has options.

7. Sedatives and Sleep Medications

Benzodiazepines like diazepam, lorazepam, and alprazolam cause bladder problems two ways. First, they relax the pelvic floor muscles and sphincter via GABA receptors, leading to leaking. Second, the sedation means you may not wake up or reach the bathroom in time 15.

One study found benzodiazepines in 17.4% of older patients seeking care for incontinence 16.

My assessment: If you’re taking a benzodiazepine and struggling with nighttime incontinence, the connection is likely. Talk to your doctor about alternatives, especially if you’re over 65.

8. Inhaled Medications for COPD and Asthma

Anticholinergic inhalers like ipratropium (Atrovent) and tiotropium (Spiriva) can cause bladder problems beyond the lungs. A systematic review found they increase the risk of acute urinary retention by 40%, with the risk highest in the first month and in men with prostate issues 17.

Practical advice: If you have a history of urinary retention and you’re prescribed an anticholinergic inhaler, mention it to your pulmonologist. Beta-agonist inhalers don’t carry the same risk.

How to Identify Which Medication Is Causing Bladder Problems

Figuring out which medications cause bladder problems in your specific case takes some detective work. Here’s a practical approach:

Check the timeline. Did your symptoms start or worsen within days to weeks of starting a new medication or changing a dose? This is the single most useful clue.
Read the leaflet. Look for “urinary retention,” “urinary frequency,” “incontinence,” or “urinary hesitancy” in the side effects section.
Consider the total load. Taking two or three medications with mild bladder effects can add up to significant bladder problems. This cumulative anticholinergic burden is especially common in older adults on multiple prescriptions.
Keep a bladder diary. Track your fluid intake, medications, and bathroom visits for a week. This gives your doctor concrete data to work with.
Ask your pharmacist. Pharmacists are trained to spot drug interactions and side effects. They can review your full medication list and flag drugs known to cause bladder problems.

When to See a Doctor

See a doctor promptly if you experience:

Complete inability to urinate (this is a medical emergency)
Blood in your urine (hematuria)
Severe pain with urination (dysuria)
New incontinence that started after beginning a medication
Urinary symptoms accompanied by fever, which could signal infection

Never stop a prescribed medication without medical guidance. Some drugs require gradual tapering, and the condition being treated may be more dangerous than the side effect. Your doctor can adjust doses, switch medications, or add treatments to manage the urinary side effects.

Frequently Asked Questions

Can over-the-counter medications really cause serious bladder problems?

Yes. Some of the worst offenders are available without a prescription. Diphenhydramine (Benadryl), pseudoephedrine (Sudafed), and doxylamine (NyQuil) can all cause urinary retention or incontinence, particularly in people over 50 or those with existing conditions like benign prostatic hyperplasia. Always check the active ingredients in OTC medications.

How long after starting a medication do bladder side effects appear?

It varies by drug. Antihistamines and decongestants can cause retention within 48 hours. Antidepressants may take weeks to affect bladder function. Diuretics cause immediate increases in urine output. If symptoms developed within a few weeks of any medication change, the timing is suspicious.

Will my bladder go back to normal if I stop the medication?

In most cases, yes. Medication-induced bladder problems are generally reversible once the offending drug is discontinued or replaced. The timeline for recovery depends on the medication’s half-life and how long you’ve been taking it. Always consult your doctor before stopping any prescribed medication.

I take multiple medications. How do I know which one is causing my bladder problems?

This is where it gets tricky. Polypharmacy, taking several medications simultaneously, is a common cause of bladder symptoms in older adults. Each drug might have mild effects individually, but together they compound. A pharmacist or geriatrician can review your full medication list and identify the cumulative anticholinergic burden.

Are there blood pressure medications that don’t cause bladder problems?

ARBs (angiotensin receptor blockers) and certain beta-blockers tend to cause fewer bladder problems than alpha-blockers, diuretics, and calcium channel blockers. Your doctor can tailor your blood pressure regimen to minimize urinary side effects.

Pulling It All Together

The medications most likely to cause bladder problems are antihistamines, decongestants, diuretics, and drugs with anticholinergic properties. Older adults are at highest risk because they tend to take more medications and their bodies process drugs more slowly.

The evidence is clearest for:

First-generation antihistamines causing retention and incontinence
Loop diuretics causing urgency and frequency
Alpha-blockers causing incontinence in women
Opioids causing retention through multiple mechanisms
Pseudoephedrine causing retention, especially in men over 50

If you’re experiencing new or worsening bladder symptoms, a medication review should be one of the first steps. Bring a complete list of everything you take, including OTC drugs and supplements, to your next doctor’s appointment. The fix might be simpler than you think.

References

Pharmacovigilance evidence of drug induced urinary incontinence in the FDA adverse event reporting system - Scientific Reports (2025)
Associations of commonly-used medications with urinary incontinence in a community-based sample - BMC Urology (2012)
Urinary retention triggered by dimenhydrinate: A case report - Urology Case Reports (2023)
Voiding dysfunction in patients with nasal congestion treated with pseudoephedrine - Urology (2016)
Acute urinary retention due to pseudoephedrine hydrochloride in a 3-year-old child - Southern Medical Journal (2008)
Bladder Symptoms Provoked by Short, Rapid-Acting Loop Diuretics - American Journal of Hypertension (2025)
Selective serotonin reuptake inhibitor-induced urinary incontinence - Pharmacotherapy (2002)
Urinary side effects of psychotropic drugs: A systematic review and meta-analysis - Neurourology and Urodynamics (2021)
Alpha-adrenoceptor blocking drugs and female urinary incontinence - British Journal of Urology (1996)
Calcium Channel Blockers Are Associated with Nocturia in Men Aged 40 Years or Older - International Neurourology Journal (2021)
Stress urinary incontinence due to prescription medications - Obstetrics and Gynecology (1998)
Drug-induced urinary retention: incidence, management and prevention - Drug Safety (2008)
Effects of opioids and benzodiazepines on bladder function - Frontiers in Pharmacology (2022)
Reversal of opioid-induced bladder dysfunction by intravenous naloxone and methylnaltrexone - Clinical Pharmacology and Therapeutics (2007)
Benzodiazepines and the risk of urinary incontinence in frail older persons - BMC Geriatrics (2002)
Prevalence of commonly prescribed medications potentially contributing to urinary symptoms - BMC Geriatrics (2013)
Risk of acute urinary retention associated with inhaled anticholinergics - BMJ Open (2014)