Elmiron (pentosan polysulfate sodium) is a prescription drug used for the treatment of bladder inflammation in people with interstitial cystitis. Elmiron was first approved by the FDA in 1985, and for years was thought to be entirely safe. Unfortunately, in 2019, researchers determined that long-term use of the drug may cause a degenerative eye disorder, pigmentary maculopathy, which may lead to vision loss or blindness.