Glycosaminoglycan-like agent (interstitial cystitis) Pregnancy: Adequate and well-controlled studies have not been performed in pregnant women; animal reproduction studies did not reveal evidence of impaired fertility or harm to the fetus. Because animal studies are not always predictive of human response, use in pregnancy only if clearly needed (US PI).

Pentosan polysulfate sodium

Brand names: Elmiron

Pentosan polysulfate sodium is an oral heparinoid used specifically to relieve bladder pain or discomfort in interstitial cystitis (bladder pain syndrome).

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 300 mg daily, given as one 100 mg capsule three times daily

Route: Oral

Frequency: Three times daily

US prescribing information (ELMIRON, DOSAGE AND ADMINISTRATION): the recommended dose is 300 mg/day taken as one 100 mg capsule orally three times daily. The capsules should be taken with water at least 1 hour before meals or 2 hours after meals. Patients should be reassessed after 3 months; if improvement has not occurred and limiting adverse events are not present, treatment may be continued for another 3 months. The clinical value and risks of continued treatment in patients whose pain has not improved by 6 months is not known. No eMC/UK SPC was available in this bundle — US labelling may differ from UK; clinician to verify against the UK SPC. Paediatric: safety and effectiveness in patients below the age of 16 years have not been established. No renal or hepatic dose adjustment appears in the retrieved sections. Note: the ADVERSE REACTIONS section was truncated at the source fetch limit, so the side-effect list below is partial.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known hypersensitivity to the drug, to structurally related compounds, or to excipients

Side effects

Insomnia
Headache
Severe emotional lability / depression
Abdominal pain
Diarrhoea (severe abdominal pain or diarrhoea with dehydration requiring hospitalisation was reported in 2 of 2627 patients)

Interactions

Warfarin — in healthy subjects given pentosan polysulfate sodium 100 mg every 8 hours for 7 days and titrated with warfarin to an INR of 1.4 to 1.8, R- and S-warfarin pharmacokinetics and INR were comparable with and without pentosan polysulfate sodium
Other therapies with anticoagulant effects — see the label PRECAUTIONS section before co-prescribing

Clinical monograph

How it works

It is thought to adhere to and replenish the deficient glycosaminoglycan layer of the bladder urothelium, restoring its protective barrier against irritant urinary solutes.

Prescribing in practice

Prolonged use has been associated with a retinal disorder (pigmentary maculopathy), so the MHRA advises baseline and regular ophthalmic monitoring and stopping if retinal changes occur.
As a weak anticoagulant heparinoid it may increase bleeding risk, so use cautiously with other anticoagulants or in patients at bleeding risk.
It is a slow-acting treatment, and response should be reviewed after an adequate trial before deciding to continue.

Monitoring

Arrange baseline and periodic retinal (ophthalmological) examination during long-term use and watch for bleeding or visual symptoms.

Counselling the patient

Benefit builds gradually over months, so persistence is usually needed.
Attend recommended eye checks and report any change in vision such as difficulty reading or adapting to dim light.

Evidence & guidelines

Pentosan polysulfate is licensed for bladder pain of interstitial cystitis; MHRA safety advice highlights the risk of pigmentary maculopathy with long-term use.

Reference: MHRA Drug Safety Update; EAU/ESSIC interstitial cystitis guidelines; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways