What the label lists and what reports show
Pentosan polysulfate side effects
Pentosan polysulfate's FDA label lists its adverse reactions in its own words. FAERS holds 6,909 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is maculopathy (1,396 reports).
- No generic listed
Check it at the source: the pentosan polysulfate FDA label on DailyMed (effective September 18, 2024, Janssen Pharmaceuticals, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of ELMIRON?Serious side effects have been reported with the use of ELMIRON, including: Changes in the retina of the eye Increased bleeding (See " What is the most important information I should know about ELMIRON? ") The most common side effects of ELMIRON are: hair loss diarrhea nausea stomach pain upset stomach headache rash abnormal liver function tests dizziness These are not all of the possible side effects of ELMIRON. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Source: FDA drug label, Janssen Pharmaceuticals, Inc., effective September 18, 2024 (SPL set f0ba651e-3d8a-11df-8fbe-119855d89593), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsELMIRON ® was evaluated in clinical trials in a total of 2627 patients (2343 women, 262 men, 22 unknown) with a mean age of 47 [range 18 to 88 with 581 (22%) over 60 years of age]. Of the 2627 patients, 128 patients were in a 3-month trial and the remaining 2499 patients were in a long-term, unblinded trial. Deaths occurred in 6/2627 (0.2%) patients who received the drug over a period of 3 to 75 months. The deaths appear to be related to other concurrent illnesses or procedures, except in one patient for whom the cause was not known. Serious adverse events occurred in 33/2627 (1.3%) patients. Two patients had severe abdominal pain or diarrhea and dehydration that required hospitalization. …
Source: FDA drug label, Janssen Pharmaceuticals, Inc., effective September 18, 2024 (SPL set f0ba651e-3d8a-11df-8fbe-119855d89593), via openFDA; the full label on DailyMed
What do FAERS reports show?
6,909 reports list pentosan polysulfate among the medicines taken, each a report of something that happened, not proof the medicine caused it; 117 are coded as a death and 650 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Reports rose sharply in 2022 (1,540, against a median of 334 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens. Of the 20 reactions below, 7 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Pentosan polysulfate: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions