ELMIRON
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ELMIRON (ELMIRON).
Elmiron (pentosan polysulfate sodium) is a low molecular weight heparin-like compound that adheres to the bladder wall, providing a protective coating to the urothelium. It is thought to reduce bladder wall permeability and inhibit mast cell histamine release.
| Metabolism | Metabolized by desulfation in the liver and spleen; undergoes partial depolymerization. The exact metabolic pathways and enzymes are not fully characterized. |
| Excretion | Primarily eliminated unchanged in urine (~90% as parent drug, ~5% as metabolites); renal excretion accounts for >95% of elimination. Fecal excretion is minimal (<5%). |
| Half-life | Terminal elimination half-life is approximately 4 hours (range 3-6 hours). Clinical context: Short half-life supports twice-daily dosing; steady-state achieved within 24-48 hours. |
| Protein binding | ~50% bound to albumin. Binding is moderate and not saturable at therapeutic concentrations. |
| Volume of Distribution | Approximately 1.5 L/kg. This large Vd indicates extensive tissue distribution, likely due to binding to glycosaminoglycan sites in bladder urothelium. |
| Bioavailability | Oral bioavailability is approximately 20-30% due to first-pass metabolism and limited absorption. Bioavailability is dose-proportional over the therapeutic range (100-200 mg three times daily). |
| Onset of Action | Oral: Onset of clinical effect (symptom relief in interstitial cystitis) may require 2-4 weeks of continuous therapy. Single-dose acute effects are not observed. |
| Duration of Action | Duration of action is sustained over the dosing interval of 12 hours with consistent twice-daily dosing. Clinical benefit requires prolonged treatment (up to 3-6 months) for maximal effect. |
100 mg orally three times daily, at least 1 hour before meals or 2 hours after meals.
| Dosage form | CAPSULE |
| Renal impairment | No specific dose adjustment recommended; use caution in severe renal impairment (CrCl <30 mL/min) due to lack of data. |
| Liver impairment | No specific dose adjustment recommended; use caution in severe hepatic impairment (Child-Pugh class C) due to lack of data. |
| Pediatric use | Safety and efficacy not established; use not recommended in patients <18 years. |
| Geriatric use | No specific dose adjustment recommended; consider age-related decline in renal function and monitor for adverse effects. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ELMIRON (ELMIRON).
| Breastfeeding | Unknown if excreted in human milk. Caution advised. No M/P ratio available. |
| Teratogenic Risk | Pregnancy Category B. No evidence of teratogenicity in animal studies; however, insufficient human data exist. Risk cannot be excluded. Use only if clearly needed. |
| Fetal Monitoring | Monitor for hypersensitivity reactions, abdominal pain, diarrhea, headache, and thrombotic events. No specific fetal monitoring required. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to pentosan polysulfate sodium or any component of the formulation.
| Precautions | Risk of retinal pigmentary changes and vision loss (pigmentary maculopathy); requires baseline and periodic ophthalmologic examinations. May increase bleeding risk; use with caution in patients with bleeding disorders or on anticoagulants. Hemorrhagic cystitis reported. Injection site reactions (for subcutaneous use) include hematoma and pruritus. |
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| Fertility Effects | No known impact on fertility in animal studies; human data lacking. |