Research conducted by Emory Eye Center at the Emory School of Medicine in Atlanta found that long-term use of the pentosan polysulfate PPS (marketed under the name Elmiron) leads to a condition known as retinal maculopathy, or retinal injury, in some long-term users of pentosan polysulfate sodium. The study concludes that patients who undertook a long-term use regimen of pentosan polysulfate sodium to see an ophthalmologist for evaluation.
As Science Daily reports, “Last year, Nieraj Jain, M.D., of Emory Eye Center in Atlanta, Ga., reported that six patients who had been taking Elmiron for about 15 years had developed unusual changes in their macula, the central part of the retina responsible for delivering the clear, crisp, central vision. Because nothing in the patient’s medical history or diagnostic tests explained the subtle but striking pattern of abnormalities, Dr. Jain and his colleagues warned that long-term use of Elmiron may damage the retina.”
Doctors prescribe Elmiron or pentosan polysulfate sodium to treat problems such as interstitial cystitis (bladder pain or discomfort) and osteoarthritis and to prevent blood clots. About interstitial cystitis, Science Daily reports, “Interstitial cystitis causes chronic pain in the bladder and pelvis area. More than 1 million people in the United States, mostly women, are estimated to have the condition. Elmiron is the only FDA-approved pill to treat it. As a mainstay of treatment for decades, hundreds of thousands of people have likely been exposed to the drug.”
The occurrence of problems related to vision and patients who take Elmiron were first observed in a cohort of 60-year-old plus patients, all of whom were diagnosed with interstitial cystitis and taking the drug as part of a treatment. An article published in the November 2018 edition of Ophthalmology outlined this case in detail. The abstract titled “Pigmentary Maculopathy Associated with Chronic Exposure to Pentosan Polysulfate Sodium” concluded that if patients had not taken pentosan polysulfate sodium, they would likely not experience the degenerative effects associated with pigmentary maculopathy.
There are three primary or general types of pigmentary maculopathy looked at by the researchers in this study. These include DHRD (Doyne Honeycomb Retinal Dystrophy), macular degeneration brought on by aging, and cellophane maculopathy. The first type, DHRD, is an inherited maculopathy that results in “pale spots” in the center of the eye that can grow into the shape of a honeycomb. At the same time, macular degeneration brought about by aging results in a clouded vision in the center of the eye. Cellophane maculopathy is when clear scar tissue forms over the retina’s center, the area of the eye associated with visual ability and sensitivity to light intensity.
Aside from the research data, the Food and Drug Administration Adverse Event Reporting System (FAERS) received 100 reported cases of eye problems associated with patients taking pentosan polysulfate sodium, with at least 22 labeled cases as “serious.” Of course, these aren’t the only problems and side effects associated with taking pentosan polysulfate sodium for long periods. Other conditions observed by research include vitelliform deposits, retina dark spots, parafoveal pigmented eye deposits, retinal pigment epithelium atrophy, hair loss, skin rashes, headaches, sleep disorders, GERD, bruising, and diarrhea.
Physicians often recognize vitelliform deposits as one of the many signs of macular dystrophy. At the same time, eye doctors typically spot dark pigmented spots on the retina during a routine examination of a patient’s eyes. Parafoveal pigmented eye deposits occur when an injury happens to the blood vessels and capillaries around the macula. The atrophy of the retinal pigment epithelium is often associated with aging and is when a patient’s retinal pigment begins to lose effectiveness. As for the other disorders associated with this phenomenon, they are self-explanatory.
Another finding is that the dosage amount of pentosan polysulfate sodium impacts the level or degree to which patients report symptoms and their severity. Research shows that higher dosages of the drug are associated with an increased incidence of the problems reported. The typical drug amount administered was 300mg in 100mg tablets three times per day. However, doctors could prescribe as much as 1,000 to 1,500mg daily. The retinal cells in patients apparently absorb the toxic elements in this drug, which leads to the reported eye problems.
Commenting on the research by Drs. Vora, Patel, and Melles, Science Daily wrote: “They found 140 patients who had taken an average of 5,000 pills each over the course of 15 years. Of those 140 patients, 91 agreed to come in for an exam. Drs. Vora, Patel, and Melles took detailed images of the back of their eyes and then divided the images into three categories: normal, possible abnormality, definite abnormality. Twenty-two of the 91 patients showed clear signs of drug toxicity. The toxicity rate rose with the amount of drug consumed, from 11 percent of those taking 500 to 1,000 grams to 42 percent of those taking 1,500 grams or more.”
While the cohort studied was primarily made up of older people, one patient began experiencing vision and eye problems as young as thirty. Dr. Robin A. Vora, MD, comments, “It’s unfortunate. You have a patient with a chronic condition like interstitial cystitis, for which there is no cure or effective treatment. They get put on these medications because it’s thought to have few side effects and few risks, and no one thinks about it again. And year after year, the number of pills they’re taking goes up and up.”
Because of the limited number of treatment options for people with interstitial cystitis, Dr. Vora recommends annual screenings for macular degeneration in patients taking or taking pentosan polysulfate sodium. One silver lining to all of this is that if action is taken early enough, damage can be mitigated and even potentially reversed.