Bladder Mucosal Protectant 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. Should be used in pregnancy only if clearly needed.

Pentosan Polysulfate Sodium

Brand names: Elmiron

Pentosan polysulfate sodium is an oral agent used 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/day (one 100 mg capsule three times daily)

Route: Oral

Frequency: Three times daily

US labelling (ELMIRON, Janssen, label date 2024-09-18) — no UK SPC was retrieved in the source bundle, so this regimen must be verified against the UK SPC before publication. 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 a further 3 months. The clinical value and risks of continued treatment in patients whose pain has not improved by 6 months are not known. Paediatric: safety and effectiveness in patients below the age of 16 years have not been established (no numeric paediatric dose stated in the source).

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, structurally related compounds, or excipients

Side effects

Insomnia
Headache
Severe emotional lability / depression
Severe abdominal pain (reported as a serious event requiring hospitalisation)
Diarrhoea with dehydration (reported as a serious event requiring hospitalisation)

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 1.4-1.8, R- and S-warfarin pharmacokinetics and INR were comparable with and without pentosan polysulfate sodium
Caution is advised in patients receiving other therapies with anticoagulant effects (see label PRECAUTIONS)

Clinical monograph

How it works

It is thought to act as a heparin-like agent that adheres to and helps restore the bladder urothelial glycosaminoglycan layer, reducing irritant penetration and bladder pain.

Prescribing in practice

Long-term use has been associated with pigmentary maculopathy and visual impairment, so patients should have ophthalmic assessment and prompt review of new visual symptoms, in line with MHRA advice.
As a weak anticoagulant it should be used cautiously in patients at increased risk of bleeding or undergoing procedures.
Treatment response should be reviewed and continuation justified, with discontinuation if no benefit, per the SPC.

Monitoring

Monitor symptom response and bleeding risk, and arrange regular ophthalmological examination during long-term treatment.

Counselling the patient

Attend recommended eye checks and report any change in vision, such as difficulty reading or adapting to dim light.
It may take time to notice benefit; do not stop without discussing with your clinician.
Report unusual bruising or bleeding.

Evidence & guidelines

Pentosan polysulfate sodium is a licensed option for interstitial cystitis, and the MHRA has advised on the risk of pigmentary maculopathy with long-term use.

Reference: MHRA Drug Safety Update 2020 (pentosan maculopathy); ESSIC Guidelines; EAU IC/BPS Guidelines 2024; 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