According to allegations raised in a recently filed product liability lawsuit, side effects of Elmiron caused degenerative retinal damage following long-term use of the interstitial cystitis drug by a Missouri woman, who indicates she has been left with impaired vision and a rare eye disease known as pigmentary maculopathy.

The complaint (PDF) was filed by Savannah Metzger earlier this month in the U.S. District Court for the Western District of Missouri, indicating Elmiron’s manufacturers knew or should have known of the risk of vision damage users of the bladder drug may face. However, rather than warning consumers and the medical community, the drug makers continued to sell the drug without retinal damage warnings until earlier this year.

Metzger indicates she was prescribed Elmiron from 2016 though 2020, stating she was unaware of the link between Elmiron and vision problems reported among a growing number of users in recent years

“During the relevant time periods, Plaintiff and her physicians were given no warning and had no knowledge of the serious risk of retinal damage and vision loss posed by Elmiron,” the lawsuit states. “As a result of her exposure to Elmiron, Plaintiff now suffers retinal damage, blurry vision, distorted vision, difficulty reading, dark spots in her vision, visual dimming, night blindness, and other visual symptoms.”

Elmiron (pentosan polysulfate sodium or PPS) is the only approved drug treatment for interstitial cystitis or “painful bladder syndrome”, and has been marketed as safe and effective since 1996. Although concerns existed for years among vision specialists about the risk of retina damage, Elmiron vision warnings were not added to the drug label in the U.S. until June 2020.

The label update came after a series of independent studies and case reports published in recent years highlighted cases involving visual injury and pigmentary changes in the retina among long-term users of Elmiron. The drug has been linked to reports in which users to experienced difficulty adjusting in dark light, problems reading, centralized dark spots and other complications, yet information about the risk of pigmentary maculpathy was withheld from the drug warning label for years.

The lawsuit indicates Janssen, which developed the drug, not only failed to conduct adequate testing, but advocated against pharmacokinetic (PK) testing, saying it was inappropriate for Elmiron. The company admitted that the mechanism of action of Elmiron is unknown.

“Despite study after study providing clear evidence of the dangers of PPS, Defendants failed to adequately investigate the threat that PPS poses to patients’ eyes and vision or warn patients of the risk that they would suffer retinal injury and vision impairment,” the lawsuit states.

Since most ophthalmologists were previously unaware that side effects of the bladder drug may impact the eyes, a growing number of Elmiron lawsuits are just now being filed as former users learn that previously misdiagnosed retinal diseases, such as macular degeneration, pattern dystrophy and other problems, were actually caused by the toxic effects of the drug on the eyes.

As Elmiron lawyers continue to review and file claims in the coming months and years, it is expected that hundreds of similar complaints may be brought in state and federal courts nationwide.