Elmiron Side Effects

The FDA’s latest available adverse events reporting showed vision problems were the most common Elmiron side effects reported by the drug’s users. Maculopathy was the single most common side effect reported to the Agency.

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 warns that people taking Elmiron may suffer from increased bleeding.

In clinical trials, the top three most common side effects were alopecia, diarrhea and nausea. Most Elmiron side effects are mild and stop after the body gets used to the medication. Many people tolerate the medication well.

Researchers studied Elmiron side effects in 2,627 patients, according to the drug’s prescribing information. Common side effects occurred in 1% to 4% of 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 trials, 1192, were followed for three months. Researchers followed the smallest number of people, 145 trial participants, for four years.

In a clinical trial with 33 patients, about 1.3% suffered serious side effects. These included abdominal pain that required hospitalization. Of those 33 patients, six died, but other health problems appear to have caused the deaths.

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

Abnormal liver function may be associated with Elmiron. In a phase 2 study, six out of 51 patients (11.8%) had increases in their liver function tests with a daily dose of 900 mg.

Rectal hemorrhage was reported in a phase 4 study of 128 patients. 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 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.

In June 2020, Janssen Pharmaceuticals added a warning for retinal pigmentary changes, also known as pigmentary maculopathy, associated with long-term Elmiron 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 Sept. 30, 2023, showed 812 cases of maculopathy, 704 cases of pigmentary maculopathy and 622 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 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 where initially no Elmiron maculopathy was detected. However, just two years later, the disease had progressed rapidly, and “advanced features of PPS (pentosan polysulfate sodium) 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.

People who experienced vision damage filed Elmiron lawsuits against Janssen Pharmaceuticals. Lawsuits claim the drugmaker failed to warn them about the risk.