Pentosan polysulfate, sold under the brand name Elmiron among others, is a medication used for the treatment of interstitial cystitis. Zycosan, for horses, is a heparin-like compound and is the first injectable pentosan product to receive approval by the US Food and Drug Administration (FDA). Medical uses Pentosan polysulfate sodium is indicated for the relief of bladder pain or discomfort associated with interstitial cystitis. Adverse effects Patients who have taken pentosan polysulfate orally report a variety of side effects, primarily gastrointestinal complaints such as diarrhea, heartburn, and stomach pain. Hair loss, headache, rash, and insomnia have also been reported. Due to Elmiron's anticoagulant effects, some patients report bruising more easily. In some cases, patients are asked to stop taking the medication before any major surgical procedures to reduce the likelihood of bleeding. Recent report based on clinical observation hypothesizes that chronic exposure to pentosan polysulfate can cause retinal toxicity, mimicking pigmentary pattern dystrophy. Mechanism of action In interstitial cystitis, pentosan polysulfate is believed to work by providing a protective coating to the damaged bladder wall. Pentosan polysulfate is similar in structure to the natural glycosaminoglycan coating of the inner lining of the bladder, and may replace or repair the lining, reducing its permeability. History The calcium salt of pentosan polysulfate was one of the first reported disease-modifying osteoarthritis drugs (DMOAD). Society and culture Names The IUPAC name for pentosan polysulfate is [(2R,3R,4S,5R)-2-hydroxy-5-[(2S,3R,4S,5R)-5-hydroxy-3,4-disulfooxyoxan-2-yl]oxy-3-sulfooxyoxan-4-yl] hydrogen sulfate. There are 40 synonyms listed for pentosan polysulfate on PubChem including BAY-946, HOE-946, pentosan sulfuric polyester, polypentose sulfate, polysulfated xylan, PZ-68, SP-54, xylan SP54 and xylan sulfate. Various brand names include Elmiron (as sodium salt), Hemoclar, Anarthron, Fibrase, Fibrocid, Thrombocid and SP54. Pentosan polysulfate capsules are sold in India under the brand names Comfora, Pentossan-100, Cystopen and For-IC. In the veterinary field, pentosan polysulfate is sold as Cartrophen Vet and Sylvet by Biopharm Australia, Pentosan by Naturevet Australia, Anarthron by Randlab Australia and Zydax by Parnell. Research Osteoarthritis Pentosan polysulfate has been studied in knee osteoarthritis, though evidence to support such use is poor as of 2003. There is some theoretical evidence that it should help. Transmissible spongiform encephalopathies Pentosan polysulfate is being studied as a potential treatment of Creutzfeldt–Jakob disease (CJD). The rationale for this treatment was unclear but it was subsequently shown in prion-infected mouse neuroblastoma cells that pentosan polysulfate could rapidly reduce the levels of abnormal (scrapie) prion without affecting the normal cellular