My husband’s doctor has recommended DMSO. He urinates frequently and sometimes cannot sleep because he keeps getting up at night. Could this be related to his prostate? He also frequently uses painkillers. Can pain medicines cause his prostate to enlarge?
Quick Answer
- Frequent urination and waking repeatedly at night can occur with an enlarged prostate (BPH), but these symptoms are not specific to BPH.
- DMSO is not an established treatment for enlarged prostate. Prescription intravesical DMSO is used for symptomatic treatment of interstitial cystitis/bladder pain syndrome.
- If his doctor is planning a DMSO bladder instillation, ask which bladder diagnosis is being treated.
- Painkillers do not normally cause the prostate itself to enlarge.
- However, some medicines—including opioids and certain other medications—can make bladder emptying more difficult and contribute to urinary retention.
- If he ever becomes completely unable to urinate, that requires urgent medical assessment.
What Is DMSO?
DMSO stands for dimethyl sulfoxide.
It is an organic sulfur-containing compound, but it is misleading to describe medically prescribed DMSO merely as an industrial by-product.
In the United States, a sterile prescription formulation called RIMSO-50 contains 50% dimethyl sulfoxide and is designed for intravesical instillation—meaning the solution is placed directly into the bladder through a catheter.
Does DMSO Treat an Enlarged Prostate?
No established medical guideline recommends DMSO as a treatment for benign prostatic hyperplasia (BPH).
The FDA-approved prescription DMSO product is indicated for symptomatic relief of interstitial cystitis.
Its prescribing information specifically states that it has not been established as safe and effective for other indications.
DMSO therefore should not be described as a medicine that shrinks an enlarged prostate or opens a prostate-blocked urethra.
Standard treatment for BPH may instead involve lifestyle measures, medications, minimally invasive procedures or surgery depending on symptom severity and complications.
Why Might a Urologist Recommend DMSO?
One reason is a diagnosis of interstitial cystitis/bladder pain syndrome (IC/BPS).
IC/BPS is a chronic bladder condition associated with symptoms such as:
- bladder pain, pressure or discomfort;
- urinary frequency;
- urinary urgency;
- pelvic discomfort;
- and symptoms that may worsen as the bladder fills.
The American Urological Association includes intravesical DMSO among the bladder-instilled treatment options that may be considered for selected patients with IC/BPS.
DMSO Does Not Tell Us the Diagnosis by Itself
I cannot determine why your husband’s doctor recommended DMSO without seeing his medical records. Ask specifically whether the treatment is intended for interstitial cystitis/bladder pain syndrome or another diagnosed bladder condition.
Interstitial Cystitis Is Not the Same as a Urinary Infection
This distinction is important.
The word cystitis is sometimes loosely used to mean any bladder inflammation, but interstitial cystitis/bladder pain syndrome is not the same condition as an ordinary bacterial urinary tract infection.
Prescription DMSO is not an antibiotic, and its current prescribing information states that there is no clinical evidence that it effectively treats bacterial urinary tract infections.
If infection is suspected, urine testing and appropriate infection treatment may be required instead.
Can an Enlarged Prostate Cause Frequent Nighttime Urination?
Yes.
Benign prostatic hyperplasia can cause lower urinary tract symptoms including:
- frequent urination;
- urgency;
- nocturia — waking at night to urinate;
- difficulty starting the urine stream;
- weak or interrupted flow;
- dribbling;
- and incomplete bladder emptying.
But frequent urination and nocturia do not prove that the prostate is the cause.
What Else Can Cause Frequent Urination or Nocturia?
Other possibilities include:
- overactive bladder;
- urinary tract infection;
- prostatitis;
- diabetes or high blood glucose;
- excessive evening fluid intake;
- alcohol or caffeine;
- diuretic medicines;
- sleep disorders including sleep apnea;
- heart or circulation problems that cause fluid to accumulate in the legs;
- bladder stones or other bladder disease;
- and neurological conditions affecting bladder function.
Can Pain Pills Cause the Prostate to Enlarge?
Pain medicines are not recognized as a usual cause of BPH or actual prostate growth.
BPH becomes more common with aging and appears to be influenced by age-related hormonal and cellular changes.
However, medicines can affect urination without physically enlarging the prostate.
This distinction is important:
| Problem | What Happens? | Is the Prostate Actually Enlarging? |
|---|---|---|
| BPH | Prostate tissue grows and may narrow the urethral outlet. | Yes |
| Medication-related urinary retention | A medicine may weaken bladder contraction or increase resistance to urine flow. | No |
| Interstitial cystitis / bladder pain syndrome | Chronic bladder-associated pain, pressure and urinary symptoms. | No |
Can Opioid Painkillers Make Urination Difficult?
Yes.
Opioid pain medicines can interfere with normal bladder emptying and are recognized as one possible medication-related cause of urinary retention.
Examples of opioid medicines include:
- morphine;
- oxycodone;
- hydrocodone;
- codeine;
- tramadol;
- and related medicines.
In someone who already has bladder-outlet obstruction from BPH, a medicine that further interferes with bladder emptying may make urinary symptoms more noticeable.
The Medicine May Worsen Urination Without Enlarging the Prostate
A man can therefore correctly notice that his urinary symptoms became worse after starting a pain medicine while still being incorrect to conclude that the medicine made his prostate physically larger.
What About Ibuprofen, Aspirin and Other NSAID Painkillers?
Nonsteroidal anti-inflammatory drugs (NSAIDs) are different from opioids.
They do not normally cause BPH, but urinary retention has been reported with several classes of medicines, and NIDDK includes NSAIDs among medicines that may contribute to urinary retention in susceptible individuals.
Frequent or prolonged NSAID use also deserves medical review for reasons unrelated to the prostate because these medicines can affect the gastrointestinal tract, kidneys, blood pressure and cardiovascular risk in some patients.
Find Out Which “Pain Pills” He Is Actually Taking
The words painkiller or pain pill are not specific enough. The doctor should know the exact medicine, dose, frequency and reason for taking it.
What Is Urinary Retention?
Urinary retention means the bladder cannot empty normally.
It may be:
- chronic — the person still urinates but leaves significant urine behind; or
- acute — the person suddenly cannot urinate at all.
Men with BPH are at increased risk because the enlarged prostate can obstruct urine flow.
Medicines that interfere with bladder or urethral function can sometimes add to that problem.
What Should Be Checked in a Man With Frequent Nighttime Urination?
If symptoms are frequent enough to repeatedly disturb sleep, I would not simply assume they are caused by BPH.
Depending on the clinical situation, evaluation may include:
- a detailed history of urinary symptoms;
- review of all prescription and non-prescription medicines;
- physical examination;
- urinalysis to look for infection, blood or other abnormalities;
- assessment of prostate and urinary function ;
- post-void residual urine measurement when appropriate;
- urine-flow testing in selected men;
- blood glucose testing when diabetes is a possibility;
- and additional bladder or prostate testing according to findings.
What Happens During Prescription DMSO Bladder Treatment?
Pharmaceutical intravesical DMSO is placed into the bladder through a catheter by a healthcare professional.
Current prescribing information for RIMSO-50 describes a 50% DMSO solution intended specifically for bladder instillation.
Possible effects can include:
- temporary bladder discomfort or spasm;
- a garlic-like taste;
- and a characteristic odor on the breath or skin that may persist after treatment.
DMSO can also increase absorption of other substances, which is one reason intravesical treatment should be supervised by an experienced clinician.
Do Not Self-Treat BPH With DMSO
Do not place non-prescription, industrial, veterinary or topical DMSO into the bladder or use it as a substitute for prescribed BPH treatment.
When Does Difficulty Urinating Need Urgent Care?
Seek prompt medical help if your husband:
- cannot urinate at all;
- develops a painful, increasingly full lower abdomen;
- has fever or chills with painful or frequent urination;
- has visible blood in the urine;
- develops severe urinary or pelvic pain;
- or becomes seriously unwell.
Acute urinary retention generally requires bladder drainage and medical evaluation rather than waiting for the symptom to resolve by itself.
Dr. Albana’s Answer
Hello,
Your husband’s frequent urination and waking repeatedly at night could be related to an enlarged prostate, but these symptoms can also come from the bladder, medicines, diabetes, infection or several other conditions.
I would first ask his doctor exactly why DMSO has been recommended. Prescription DMSO placed into the bladder is primarily used for selected patients with interstitial cystitis/bladder pain syndrome. It is not a standard medicine for shrinking an enlarged prostate.
Regarding his pain medicines, they are unlikely to have caused his prostate itself to grow. However, certain pain medicines—particularly opioids—can make bladder emptying more difficult and may contribute to urinary retention. Other medicines can do this as well.
Therefore, I would bring a complete list of everything he takes, including over-the-counter painkillers, to his next appointment.
If his symptoms are significantly disturbing his sleep, it would also be reasonable to review his urine, bladder emptying, prostate symptoms and other possible causes of nocturia rather than assuming the prostate is responsible.
— Dr. Albana Greca, MD, MMedSc, Family Physician / General Practitioner
Most Asked Questions About DMSO, BPH and Painkillers
Does DMSO shrink an enlarged prostate?
DMSO is not an established treatment for shrinking BPH. Prescription intravesical DMSO is used for symptomatic treatment of interstitial cystitis/bladder pain syndrome.
Why would a urologist put DMSO into the bladder?
One recognized use is intravesical treatment for interstitial cystitis/bladder pain syndrome. Ask the treating urologist which diagnosis is being treated in your particular case.
Can painkillers enlarge the prostate?
Pain medicines are not a usual cause of actual prostate growth. However, some can interfere with bladder emptying and worsen urinary symptoms without enlarging the prostate.
Can opioids cause urinary retention?
Yes. Opioids are among the medicines that can contribute to urinary retention. Men who already have BPH may be particularly susceptible to worsening difficulty emptying the bladder.
Can ibuprofen cause an enlarged prostate?
Ibuprofen does not normally cause BPH. However, NSAIDs are among several classes of medicines that have been associated with urinary retention in susceptible people.
Does waking several times at night mean I have BPH?
Not necessarily. Nocturia can occur with BPH, but also with bladder disorders, diabetes, sleep apnea, medication use, excessive evening fluids and several other conditions.
Is DMSO used to treat a urinary tract infection?
No. Prescription DMSO is not an antibiotic, and its prescribing information does not establish it as an effective treatment for bacterial urinary tract infections.
When is difficulty urinating an emergency?
Complete inability to urinate is acute urinary retention and requires urgent medical assessment, particularly if the lower abdomen is painful and distended.
Related Enlarged Prostate Guides
Medical References
-
U.S. National Library of Medicine, DailyMed.
RIMSO-50 (dimethyl sulfoxide) intravesical solution.
Prescription information.
DailyMed -
Clemens JQ, Erickson DR, Varela NP, Lai HH.
Diagnosis and Treatment of Interstitial Cystitis/Bladder Pain
Syndrome.
Journal of Urology. 2022.
AUA / Journal of Urology -
National Institute of Diabetes and Digestive and Kidney Diseases.
Enlarged Prostate (Benign Prostatic Hyperplasia).
NIDDK -
National Institute of Diabetes and Digestive and Kidney Diseases.
Symptoms & Causes of Urinary Retention.
NIDDK -
National Institute of Diabetes and Digestive and Kidney Diseases.
Treatment of Urinary Retention.
NIDDK
Medical information notice: This page provides general health education. Frequent urination, nocturia and difficulty emptying the bladder have many possible causes. DMSO bladder treatment and changes to prescription pain medicines should only be made with the treating healthcare professional.
Written & medically reviewed by Dr. Albana Greca, MD, MMedSc • Family Physician / General Practitioner • Last medically reviewed: August 2026