Pharmacology · Class
Potassium binders !
Resins and polymers taken by mouth or enema that trap potassium in the gut so it leaves in the stool. They act slowly.
Updated 2026-11-01
What they are
Non-absorbed exchange resins and polymers that bind potassium in the intestine, mainly the colon: sodium polystyrene sulfonate, calcium polystyrene sulfonate, patiromer and sodium zirconium cyclosilicate. They treat hyperkalaemia that is not an emergency, often in chronic kidney disease or with RAAS inhibitors.
Mechanism of action
In the gut lumen the binder gives up sodium or calcium and takes potassium in exchange. Because it is not absorbed, the bound potassium leaves the body in the stool and serum potassium falls over hours to days.
Target: Potassium ions in the gut lumen (no receptor)
Drugs in this class
Others in the class
- Calcium polystyrene sulfonate
- Sodium zirconium cyclosilicate
Test yourself
Think of the answer, then tap the question to see it.
Why are potassium binders not used alone for hyperkalaemia with ECG changes?
They take hours to days to lower potassium; the emergency needs IV calcium to protect the heart and treatments that shift or remove potassium faster.
Where in the gut does sodium polystyrene sulfonate mainly exchange potassium?
Mostly in the large intestine, where it releases sodium and binds potassium that is then lost in the stool.
Which serious gastrointestinal complication is linked to sodium polystyrene sulfonate?
Intestinal necrosis, sometimes fatal, especially when combined with sorbitol.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - SODIUM POLYSTYRENE SULFONATE powder, for suspension (DailyMed (U.S. National Library of Medicine), 2026); Sodium Polystyrene Sulfonate: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2017); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.