What drugs can cause urinary retention? An in-depth guide to medication-induced bladder issues

October 11, 2025 •

3 min read

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), approximately 1 in 10 men over 70 will develop acute urinary retention. While age and prostate issues are major factors, medication is a frequent and often overlooked cause of this condition, making it crucial to understand what drugs can cause urinary retention.

Quick Summary

Several classes of medications, including anticholinergics, opioids, and alpha-adrenergic agonists, can interfere with normal bladder function, leading to urinary retention. The risk is often higher in elderly patients with pre-existing conditions like benign prostatic hyperplasia. Management may involve discontinuing the causative drug and draining the bladder.

Key Points

Medication is a Common Cause: Many common drugs, both prescription and over-the-counter, can disrupt bladder function and lead to urinary retention.
Anticholinergics are Major Culprits: Medications with anticholinergic effects, including older antihistamines, TCAs, and antispasmodics, are notorious for inhibiting bladder contraction.
Cold Medicines Pose a Risk: Over-the-counter decongestants containing sympathomimetics like pseudoephedrine can increase the tone of the urethral sphincter, obstructing urine flow.
Opioids and Anesthetics: Pain medications (opioids) and some anesthetics can interfere with nerve signals and sphincter control, causing or worsening urinary retention.
Risk Factors Increase Susceptibility: Older age, male gender, and pre-existing conditions like benign prostatic hyperplasia (BPH) significantly increase the likelihood of drug-induced urinary retention.
Don't Stop Medications Abruptly: Never discontinue a prescribed medication without consulting a doctor, as there may be alternative options or strategies to manage the side effect.

The Mechanism Behind Drug-Induced Urinary Retention

Urinary retention is the inability to completely empty the bladder. This can be acute (sudden and painful) or chronic (gradual and painless). Normal urination is a complex process controlled by the central nervous system, involving coordinated muscle contraction and relaxation of the bladder and sphincters. Medications can disrupt this process in several ways, primarily by interfering with nerve signals or muscle function. This interference can lead to decreased bladder muscle contraction, increased sphincter tone, or reduced sensation of bladder fullness.

Primary Drug Classes Associated with Urinary Retention

Anticholinergic Medications

Anticholinergics block acetylcholine, a neurotransmitter that helps the bladder muscle contract, making them a significant cause of drug-induced urinary retention. Some are even used for overactive bladder, requiring careful dosing.

Examples include:

Antispasmodics (e.g., dicyclomine, oxybutynin)
Tricyclic Antidepressants (TCAs) (e.g., amitriptyline, imipramine)
First-Generation Antihistamines (e.g., diphenhydramine, chlorpheniramine)
Antiparkinsonian Agents (e.g., benztropine, trihexyphenidyl)

Sympathomimetic Agents

These drugs activate the sympathetic nervous system, causing the internal urethral sphincter to tighten and resist urine flow. Many are found in cold and sinus medications.

Common examples are:

Alpha-adrenergic agonists (e.g., pseudoephedrine, phenylephrine)
Amphetamines (e.g., amphetamine/dextroamphetamine)

Opioid Analgesics

Opioids can reduce the urge to urinate and increase sphincter tone. Constipation, a common opioid side effect, can also worsen retention.

Examples: Morphine, fentanyl, hydrocodone, and oxycodone.

Antidepressants

Besides TCAs, some other antidepressants like SSRIs can also cause urinary retention, though less commonly. This may be due to increased sympathetic activity or effects on serotonin receptors.

Examples: Fluoxetine and duloxetine.

Antipsychotic Medications

Both first- and second-generation antipsychotics can have anticholinergic effects that lead to retention.

Calcium Channel Blockers (CCBs)

CCBs can relax the bladder muscle, reducing its ability to contract and causing incomplete emptying.

Examples: Nifedipine and verapamil.

NSAIDs

NSAIDs can affect bladder contraction by inhibiting prostaglandins, potentially contributing to retention, especially in men with other risk factors.

Examples: Ibuprofen and naproxen.

Comparison of Drug Classes Causing Urinary Retention


Drug Class	Examples	Primary Mechanism	Risk Factors
Anticholinergics	Oxybutynin, Amitriptyline, Diphenhydramine	Inhibits detrusor muscle contraction	Elderly, patients with BPH
Sympathomimetics	Pseudoephedrine, Phenylephrine	Increases internal urethral sphincter tone	Men, particularly with BPH
Opioids	Morphine, Hydrocodone, Fentanyl	Reduces sensory signals, increases sphincter tone	Any user, especially post-surgery
Tricyclic Antidepressants	Imipramine, Nortriptyline	Anticholinergic effect inhibits bladder contraction	Elderly, patients with BPH
Antipsychotics	Haloperidol, Chlorpromazine, Quetiapine	Anticholinergic effects	Any user
Calcium Channel Blockers	Nifedipine, Verapamil, Diltiazem	Relaxes bladder smooth muscle	Elderly, patients with heart conditions

Important Considerations and Management

Certain factors increase the risk of drug-induced urinary retention, including older age, being male (especially with BPH), and having neurological conditions. If you suspect a medication is causing retention, consult a healthcare provider without stopping the drug yourself. A doctor will evaluate symptoms and may perform tests like a post-void residual measurement.

Management may involve medication adjustment, catheterization for acute cases, treating underlying conditions like BPH, or physical therapy.

For more detailed information on urinary retention and its causes, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) offers extensive resources. Visit their website for further reading.

Conclusion

Many common medications can cause urinary retention by interfering with bladder and sphincter function. Anticholinergics, sympathomimetics, and opioids are key culprits. Risk is higher in older men and those with BPH. Always discuss urinary symptoms with your doctor for proper diagnosis and management.

Frequently Asked Questions

Yes. Many cold medicines contain decongestants like pseudoephedrine or phenylephrine, which are sympathomimetics that can cause the bladder sphincter to tighten, leading to difficulty urinating.

Yes, older adults are at a higher risk, especially men with benign prostatic hyperplasia (BPH). Co-morbidities and polypharmacy (taking multiple medications) can increase the risk of side effects like urinary retention.

You should contact your healthcare provider immediately. Do not stop taking the medication on your own. A doctor can evaluate your symptoms, confirm the cause, and determine the safest course of action, which may involve adjusting the dose or switching medications.

No, not all antidepressants cause urinary retention, but some, particularly older tricyclic antidepressants (TCAs) and even some newer SSRIs, have been linked to it. The risk varies depending on the specific drug and individual factors.

Acute urinary retention is a medical emergency that requires immediate treatment. The primary treatment involves draining the bladder with a catheter to relieve pain and prevent long-term damage to the bladder or kidneys.

Yes. Some blood pressure medications, particularly certain calcium channel blockers, can relax the bladder muscle and decrease its ability to contract effectively, which can lead to urinary retention.

No, it is often reversible. In most cases, discontinuing or adjusting the dose of the causative medication, under a doctor's supervision, will resolve the urinary retention.