Kaliumbinder

Kaliumbinder, or potassium binders, are medications that reduce elevated blood potassium by binding potassium in the gastrointestinal tract and promoting its excretion in the stool. The most commonly used agents are patiromer and sodium zirconium cyclosilicate (ZS-9, Lokelma).

Mechanism and use: Patiromer is a non-absorbed polymer that exchanges calcium for potassium in the colon. Sodium zirconium cyclosilicate is an inorganic exchanger that binds potassium and releases hydrogen and sodium ions in the GI tract. These agents are intended to lower serum potassium in hyperkalemia and can help permit continued use of potassium-sparing therapies, such as RAAS inhibitors, in patients with chronic kidney disease or heart failure.

Administration and dosing: They are taken orally, typically with meals. Dosing is individualized based on potassium levels and response. Because these drugs can bind other orally administered medicines, timing is important; most guidelines recommend separating the binder from other medications by several hours (for example, patiromer often requires a gap of around 3 hours before or after other drugs).

Contraindications and precautions: Contraindications include bowel obstruction or other significant gastrointestinal motility disorders, and known hypersensitivity. Caution is warranted in patients at risk of electrolyte disturbances; patiromer can cause hypomagnesemia and, less commonly, hypercalcemia.

Side effects and interactions: Common gastrointestinal symptoms (constipation, diarrhea, nausea, abdominal pain) may occur. Both agents can affect the absorption of concurrently administered oral drugs, so dosing may need adjustment or timing changes. Regular monitoring of serum potassium, calcium, and magnesium is recommended during therapy.