Maculopathy Common With Long-Term Pentosan Polysulfate Therapy

By Will Boggs MD

January 29, 2020

NEW YORK (Reuters Health) - Long-term use of pentosan polysulfate sodium, the only oral medicine approved for interstitial cystitis, is associated with development of a unique pigmentary maculopathy, researchers report.

"All patients who take Elmiron (pentosan polysulfate) should be seen by a retina specialist," Dr. Robin A. Vora, an ophthalmologist with Kaiser Permanente Northern California (KPNC), in Oakland, told Reuters Health by email. "Patients should not rely simply on the presence or absence of visual symptoms."

A recent report linked chronic exposure to pentosan polysulfate sodium (PPS) with the development of pigmentary maculopathy, Dr. Vora and colleagues note in Ophthalmology. But retrospective database studies investigating the relationship between PPS intake and maculopathy have yielded equivocal results, they add.

The team evaluated the prevalence and risk factors for maculopathy in patients with long-term exposure to PPS in the KPNC medical record database.

They identified 475 patients with interstitial cystitis who were currently taking PPS and reached out to 138 patients who had been dispensed at least 500 g of PPS during the prior 20 years and who still had an active prescription for the medication. Ultimately, 117 of these patients were screened with optical coherence tomography (OCT) and fundus photography.

Among these patients, 27 (23.1%) had definite signs of maculopathy. Only three patients with maculopathy had reduced central vision to a level below 20/150 due to geographic atrophy involving the fovea, and visual acuity was generally preserved in the rest of the patients.

The mean amount of PPS dispensed was significantly higher in patients with maculopathy (1,350 g, or 13,510 capsules) than in patients without maculopathy (1,040 g, or 10,387 capsules).

The proportion of patients with maculopathy increased significantly with increasing cumulative dose of PPS, from 12.7% of patients exposed to 500-999 g to 41.7% of patients exposed to more than 1,500 g.

Compared with the 500-999 g group, the odds of developing maculopathy were 2.95-fold higher in the 1000-1500 g group (P=0.05) and 4.91-fold higher in the >1500 g group (P=0.01).

In multivariable analysis, the cumulative amount of PPS dispensed was the only significant factor linked to the development of maculopathy.

"Our study will help ophthalmologists provide more accurate counseling and prognostic information," Dr. Vora said. "Armed with this information, a patient can then work with their prescribing physician to decide the best next choice of action."

Dr. Nieraj Jain of Emory University School of Medicine, in Atlanta, who co-authored an earlier report of pigmentary maculopathy associated with chronic PBS exposure, told Reuters Health by email, "This study corroborates the concerns raised by earlier studies that long-term use of pentosan polysulfate is associated with a vision-threatening macular disease. In this study, over 40% of patients in the highest exposure group - equivalent to roughly 13 or more years on a typical dosing regimen - had this condition. This is alarming, as this drug has been widely prescribed for over two decades."

"Prescribers of this drug, as well as ophthalmologists, need to be educated about this condition," he said. "Prescribers should think twice about the duration of the treatment course when using this drug."

"Based on our prior studies on the topic, we have been actively screening exposed patients at our institution," said Dr. Jain, who was not involved in the new research. "The findings in this study provide valuable information that we can relay to our patients and provide further support regarding the need for routine screening evaluations."

SOURCE: Ophthalmology, online January 17, 2020.