Elmiron: Side Effects, Vision Risks & FDA Warnings

Elmiron (pentosan polysulfate sodium) is an oral medication approved by the U.S. Food and Drug Administration (FDA) for the treatment of interstitial cystitis (IC), a chronic condition causing bladder pain and discomfort.

IC is sometimes called bladder pain syndrome. Elmiron is the only FDA-approved oral treatment for IC, a disease that affects up to 12 million people in the U.S. More women than men have IC, which predominantly affects adults

Due to the persistent nature of IC, doctors may prescribe Elmiron for long-term use. Research published in the journal Ophthalmology found that roughly 1 in 4 people taking Elmiron for five years or longer developed significant retina damage. The retina is a thin layer at the back of the eye that senses light. It sends signals to the brain through the optic nerve, helping us see images.

Concerns over vision damage led the FDA to add a black box warning (the agency’s most serious alert) to Elmiron’s label. These issues have also resulted in nearly 2,000 Elmiron lawsuits claiming vision injury, including over 900 pending lawsuits.

Common side effects of Elmiron may include diarrhea, hair loss, nausea, abdominal pain and headaches. Most Elmiron side effects are mild and stop after the body gets used to the medication. Many people tolerate the medication well.

In clinical trials, the top three most common side effects were alopecia, diarrhea and nausea.

Researchers studied Elmiron side effects in 2,627 patients with a mean age of 47, according to the drug’s prescribing information. Of these 2627 patients, 128 were involved in a 3-month trial and the remaining 2499 patients were part of a long-term, unblinded trial. Common side effects occurred in 1% to 4% of these 2499 participants.

The top side effect reported by clinical researchers was hair loss, or alopecia. Hair loss began in the first four weeks of treatment. About 97% of patients experienced hair loss in a single spot. Hair loss stopped for most patients and hair grew back after they discontinued using the drug.

The largest number of people in the 2499 patient long-term trials, 1192, were followed for three months. Researchers followed the smallest number of people, 145 trial participants, for four years.

Serious Elmiron side effects include bleeding, changes in the retina of the eye and allergic reactions.

The most concerning Elmiron side effects are linked to long-term use. Scientific research associates Elmiron with an eye disease called pigmentary maculopathy, which can lead to severe vision loss. Routine eye examinations, including retinal examinations, are suggested while taking Elmiron.

In addition, Elmiron may increase bleeding risks. Let your doctor know right away if you suddenly start experiencing nosebleeds or bleeding gums, begin bruising easily or discover blood in your stool. This is especailly important if you take warfarin, heparin, a high dose of aspirin or anti-inflammatory medicines like ibuprofen.

In a clinical trial with 33 of the original 2627 patients, about 1.3% suffered serious side effects. These included abdominal pain, dehydration and/ or diarrhea that required hospitalization. Six patients died (0.2%), but deaths appeared to be related to other concurrent illnesses or procedures, except in one patient for whom the cause was unknown.

Abnormal liver function may be associated with Elmiron. In a phase 2 study involving 100 men dosed for 16 weeks (51 participants receiving Elmiron and 49 receiving a placebo), 6 patients (11.8%) had increased values in their liver function tests with a daily dose of 900 mg. It is important to note that 900mg is higher than the approved dose of Elmiron and that 2% of placebo-treated patients also had elevated liver function tests.

Rectal hemorrhage was reported in a phase 4 study of 380 patients, 128 of whom were taking a daily dose of 300mg. Eight patients (6.3%) who took the daily 300 mg dose experienced rectal hemorrhage, but most patients described it as “mild”. Among people who took a 900 mg daily dose, 15% had a higher incidence of rectal bleeding.

When To Seek Medical Attention

Because Elmiron is associated with permanent vision changes and increased bleeding, talk to your medical provider right away if you experience:

Seek medical attention if you experience a serious allergic reaction with symptoms such as swelling of the throat, tongue, lips or face. This may include problems breathing, a rash, rapid heartbeat or dizziness.

Research has linked Elmiron use to pigmentary maculopathy. This condition is also known as PPS maculopathy, named after the active ingredient in Elmiron — pentosan polysulfate sodium. Avoiding Elmiron treatment is the only known way to prevent this condition.

In June 2020, Janssen Pharmaceuticals added a warning for retinal pigmentary changes, including pigmentary maculopathy, associated with long-term Elmiron use. Although most of the cases occurred after 3 years of use or longer, some cases were seen with a shorter duration of use. Increased dose and length of use appear to be risk factors.

The prescribing information recommends vision tests within six months of starting treatment and periodic tests after that. Some people continued to have progressive vision damage after stopping treatment.

“[Elmiron vision loss] might not get worse after you stop taking it, but it’s not getting better. It’s profoundly impacted these patients,” product liability attorney Trent B. Miracle told Drugwatch. “Sometimes, we’ll represent people who have other injuries, and they recover. They still have a challenging road back to recovery. But there’s a recovery, there’s a path there for a lot of those people. For these clients that took Elmiron, there isn’t one. And that’s a different conversation to have with people.”

The most recently available information published to FAERS on July 7, 2025, showed 938 cases of maculopathy, 837 cases of pigmentary maculopathy and 608 cases of retinal pigmentation as the top adverse events. However, since this data wasn’t gathered in a controlled environment, causation can’t be established.

Recent Elmiron Vision Damage Research

The most common visual symptoms reported in studies were difficulty reading and difficulty adapting to dim lighting. Researchers found that PPS (pentosan polysulfate sodium) users who took more of the drug over a longer period of time had the worst eye damage and that damage could continue progressing even after a patient stopped taking the medicine.

Researchers in a November 2023 case study published in Retinal Cases & Brief Reports reported on a case of an elderly patient with a history of PPS therapy (cumulative dose of 1,205g) where initially no Elmiron maculopathy was detected. However, just two years later, the disease had progressed rapidly, and “advanced features of PPS maculopathy were detected in both eyes.”

One March 2022 study in the British Journal of Clinical Pharmacology found that people who used Elmiron for more than three years had a 9.5-fold increased risk of maculopathy compared to a 2.3-fold increased risk when used for one year or less.

Pigmentary maculopathy gradually affects a part of the retina called the macula, which helps people clearly see objects directly in front of them. As the disease progresses, it can lead to serious vision problems.

The likelihood of developing pigmentary maculopathy increases based on how much Elmiron a patient takes over time. Researchers found that the risk for eye issues jumps from about 12.7% for those who took between 500 and 999 grams to as high as 41.7% for those who took over 1,500 grams. On average, people taking Elmiron receive around 100 grams each year, meaning they could potentially start to experience eye damage within three to five years.

The symptoms of Elmiron eye damage are similar to macular degeneration, a common age-related condition, which can delay proper diagnosis and treatment. It’s important to see an ophthalmologist if you experience vision problems while taking Elmiron.

In June 2020, the FDA approved changes to Elmiron’s label, adding a black box warning for pigmentary maculopathy following multiple reports of severe eye problems, including potential permanent vision loss. The FDA also recommended periodic eye exams for people taking Elmiron.

Reports related to maculopathy and macular degeneration account for more than 60% of all Elmiron adverse events reported to the FDA. In fact, according to the FDA’s latest available adverse events reporting, vision problems were the most common Elmiron side effects reported by the drug’s users. Maculopathy was the single most common Elmiron side effect reported to the agency.

Despite these warnings and a high rate of vision-related adverse event reports, Elmiron is still available in the United States as of October 2025. Elmiron’s manufacturer — Janssen Pharmaceuticals, a subsidiary of Johnson & Johnson — has not issued any Elmiron recalls or pulled the drug from the market.

There haven’t been any additional Elmiron side effect warning updates since Janssen Pharmaceuticals added a label warning for pigmentary maculopathy and changes in the retina of the eye in June 2020.

In addition to pigmentary maculopathy warnings, the drug’s label cautions that people taking Elmiron may suffer from increased bleeding. The drug is a low molecular weight heparin-like compound with anticoagulant and fibrinolytic effects. Its anticoagulant activity is considered weak, approximately 1/15th the activity of heparin. It has not been well studied in several populations, including those with hepatic insufficiency and pregnant and/or nursing mothers, so caution should be exercised when treating those individuals.

People began filing Elmiron lawsuits following research linking the drug to vision problems and the FDA’s addition of vision-related side effects to Elmiron’s label.

A federal panel combined 128 Elmiron lawsuits into a multidistrict litigation (MDL) in December 2020. An MDL allows for the consolidation of multiple similar lawsuits into a single litigation to expedite the legal process. To date, the U.S. Judicial Panel on Multidistrict Litigation has consolidated almost 2,000 lawsuits into the MDL. As of October 2025, there were 730 cases still pending.

The number of cases pending has been slowly decreasing, suggesting that Jannsen has been settling cases confidentially. Drugwatch’s legal partners are no longer accepting Elmiron cases.

What Do Elmiron Lawsuits Claim?

Elmiron lawsuits claim that the medication caused injuries to people’s retinas, particularly maculopathy.

A study of the lawsuits in the MDL, published in The Journal of Urology, examined cases from 2018 to 2023 involving people who suffered vision problems after using Elmiron. On average, these users took the medication for 13.4 years, with plaintiffs using it for between two and 25 years.

The most common injury claimed in lawsuits reviewed for the study was macular damage, accounting for 28% of the claims.

If you believe Elmiron has caused you harm, it’s crucial to prioritize your health and eyesight. Contact your doctor right away if you notice any changes in your vision, like blurriness, difficulty reading, trouble seeing in the dark, spots in your vision or distorted eyesight.

It’s a good idea to get a complete check-up with an eye doctor, especially if you’ve been using Elmiron for several months or more, as eye damage can be severe. Elmiron may also increase the risk of bleeding from surgery or dental work involving extractions or gum surgery. Always tell your doctor, dentist or other health care provider that you are taking Elmiron before undergoing surgery or dental procedures. Also, let them know about any new bruising or bleeding issues you may experience.

Keep a record of any symptoms you experience and the medications you take. Before stopping Elmiron, have a conversation with your doctor about alternative treatments. If you’re already facing problems or your vision loss is impacting your daily life, reach out to a lawyer for advice. Drugwatch is unaware of any attorneys currently accepting Elmiron lawsuits, but discussing your case with an attorney may protect your future rights.