What Is Pentosan Polysulfate?
The chemistry of pentosan polysulfate sodium, the active ingredient of Elmiron capsules, its semi-synthetic production from beechwood xylan, its relationship with the protective glycosaminoglycan layer of the bladder, and interstitial cystitis.
Definition and chemistry
Pentosan polysulfate sodium (PPS) is a semi-synthetic sulfated polysaccharide. Its starting material is xylan, a plant polysaccharide obtained from beechwood; this chain is chemically sulfated to yield the molecule.
In structure and in its high density of negative charge it resembles heparin. That resemblance is not merely a point of chemistry: it is also the reason the molecule shows weak anticoagulant activity.
In Turkey, the authorised medicinal product containing pentosan polysulfate sodium is Elmiron 100 mg hard capsules. It is a prescription-only medicine; healthcare professionals can reach the product documents through the relevant section.
- Active substance
- Pentosan polysulfate sodium
- Class
- Semi-synthetic sulfated polysaccharide
- Source
- Beechwood xylan
- Molecular weight
- Approximately 4,000–6,000 Da (distributed)
- ATC code
- G04BX15
- Legal status
- Prescription-only
The GAG layer of the bladder
The inner surface of the bladder is lined by an epithelium called the urothelium. On the side of that tissue facing the urine lies a thin, adherent coat made of glycosaminoglycans, the GAG layer for short.
The function of the GAG layer is to form a barrier. Urine contains dissolved substances, potassium foremost among them, that can irritate tissue. An intact GAG layer limits the passage of those substances into the layers beneath the urothelium.
Where this barrier thins or loses its integrity, it has been proposed that substances in the urine leak into the tissue and stimulate the nerve endings below, producing pain and a sense of urgency. This is one of the leading hypotheses put forward to explain bladder pain syndrome.
Mechanism of action
The action of pentosan polysulfate, while not fully elucidated, is explained principally by way of this barrier:
- Adherence to the mucosa: after oral administration a portion of the molecule is excreted in the urine and adheres to the inner bladder surface.
- Support of the barrier: the negatively charged chains partly substitute for a damaged GAG layer, contributing to the protective coat at the surface.
- Reduced permeability: passage of irritant solutes from the urine into the tissue beneath the urothelium is thereby expected to decrease.
- Heparin-like activity: owing to the structural resemblance the molecule also displays weak anticoagulant and anti-inflammatory properties.
Absorption is low; only a small fraction of an oral dose reaches the systemic circulation.
What is interstitial cystitis?
Interstitial cystitis (in current terminology bladder pain syndrome) is a condition marked by chronic pain, pressure or discomfort in the bladder region, accompanied by urinary frequency and a sudden sense of urgency.
The diagnosis is one of exclusion: it is reached after urinary tract infection, stones, overactive bladder and other possible causes have been ruled out. It is markedly more common in women than in men and can impose a heavy burden on quality of life.
Its cause cannot be reduced to a single heading. Alongside disruption of the GAG layer, mechanisms such as mast cell activation, neurogenic inflammation and central pain sensitisation are under consideration.
Where the safety information is held
This page describes the chemistry of the active substance and the related condition; it is not a safety reference. Warnings, undesirable effects, restrictions on use and the monitoring provided for are set out in the Summary of Product Characteristics (SmPC) and the package leaflet. Those documents are the binding source.
For prescription products these documents are addressed solely to healthcare professionals and can be reached from the Medicines page. If you are taking this substance, or considering it, discuss safety and monitoring with your doctor or pharmacist.
This page is for information only and is not product promotion. Pentosan polysulfate sodium is a prescription-only active substance. No dosage, method of administration or treatment recommendation appears on this page.
If you have symptoms, consult your doctor for assessment and for any treatment decision. No medicine should be used without medical advice.
Frequently asked questions
What is pentosan polysulfate sodium?
A semi-synthetic sulfated polysaccharide that resembles heparin in structure and in its high density of negative charge. Its ATC code is G04BX15 and it is prescription-only in Türkiye.
What is pentosan polysulfate derived from?
Its starting material is xylan, a plant polysaccharide obtained from beechwood. The molecule is produced by chemically sulfating that chain.
What is the GAG layer of the bladder?
A thin protective coat of glycosaminoglycans on the urine-facing side of the urothelium lining the bladder. Its role is to limit the passage of irritant solutes such as potassium into the tissue beneath.
What is interstitial cystitis?
Known in current terminology as bladder pain syndrome, it is a condition in which chronic pain, pressure and discomfort in the bladder region occur together with urinary frequency. The diagnosis is reached after other causes such as infection and stones have been excluded.
Is pentosan polysulfate prescription-only?
Yes. It is a prescription-only active substance in Türkiye and is used solely on medical advice. The Summary of Product Characteristics and the package leaflet are addressed to healthcare professionals.
Aymed İlaç Sanayi manufactures authorised medicinal products in urology and nephrology. Healthcare professionals can reach the Summary of Product Characteristics and package leaflet for our products from the Medicines page.