Gastrointestinal potassium binder

Class

Potassium-binding resin/crystal

Gastrointestinal potassium binders are non-absorbed compounds that act within the intestinal lumen to reduce the amount of potassium taken up into the bloodstream. Potassium levels in blood are tightly regulated because both very low and very high concentrations disrupt the electrical activity of heart and muscle cells. Elevated potassium, or hyperkalemia, is common in chronic kidney disease and heart failure, conditions in which the kidneys are less able to excrete potassium and in which patients are often treated with renin-angiotensin-aldosterone system inhibitors, a drug class that itself tends to raise potassium as a side effect. By capturing potassium ions in the gut before they can be absorbed, these binders lower circulating potassium without requiring changes to kidney function. This approach allows patients to continue on kidney- and heart-protective therapies that might otherwise need to be reduced or stopped because of hyperkalemia. The two compounds in this class differ chemically, one being a polymer-based ion-exchange resin and the other a crystalline structure, but both work through the same general principle of trapping potassium in the digestive tract and promoting its elimination through stool rather than urine.