sodium zirconium cyclosilicate in the management of hyperkalaemia

Last edited 10/2022 and last reviewed 10/2022

Sodium zirconium cyclosilicate is indicated for the treatment of hyperkalemia in adults (1)

  • is a nonabsorbed, potassium-binding, inorganic cation exchange crystalline compound formulated as an insoluble, odorless, and tasteless white powder
  • does not expand when mixed with water, unlike sodium polystyrene sulfonate, which expands to 80% to 100% of its original volume
  • as a microporous member of the zirconium silicate family of compounds, sodium zirconium cyclosilicate captures potassium through a process mimicking the action of physiologic potassium channels
  • exhibits potassium uptake over the range of pH values found in the GI tract
    • at low pH, such as that found in gastric fluid (pH of 1.2), there is rapid uptake followed by a reversal
    • as pH increases, K+ uptake is rapid and sustained
    • potassium uptake is expected to begin in the lower pH of the stomach, and uptake increases as the compound passes through the GI tract due to higher potassium concentrations and higher pH
    • binds potassium, including dietary potassium, throughout the GI tract
  • medications that have demonstrated altered pharmacokinetics when administered with sodium zirconium cyclosilicate include the weak acids furosemide and atorvastatin and the weak base dabigatran (1)
  • achieves a rapid correction of serum potassium levels (within 2 days) and maintaining normokalemia in the long term (up to 1 year), with a good safety profile (common adverse reactions include gastrointestinal events and a dose-dependent risk of edema) (2)

NICE state (3):

Sodium zirconium cyclosilicate is recommended as an option for treating hyperkalaemia in adults only if used:

  • in emergency care for acute life-threatening hyperkalaemia alongside standard care or
  • for people with persistent hyperkalaemia and chronic kidney disease stage 3b to 5 or heart failure, if they:
    • have a confirmed serum potassium level of at least 6.0 mmol/litre and
    • because of hyperkalaemia, are not taking an optimised dosage of renin-angiotensin-aldosterone system (RAAS) inhibitor and
    • are not on dialysis

Stop sodium zirconium cyclosilicate if RAAS inhibitors are no longer suitable