Pentosan polysulfate sodium

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.