Comparison of Sodium Zirconium Cyclosilicate to Sodium Polystyrene Sulfonate in the Inpatient Management of Acute Hyperkalemia

Background: Oral potassium binders have a role in the management of acute hyperkalemia among hospitalized patients. However, with therapeutic additions to this class, there is insufficient evidence between potassium binders to support a standard of care recommendation for use in this acute setting. Objective: The purpose of this study was to compare the acute potassium lowering effects of sodium zirconium cyclosilicate (SZC) and sodium polystyrene sulfonate (SPS). Methods: A retrospective review of admitted patients who received SZC or SPS was conducted after exemption from the Institutional Review Board. Patients with baseline potassium values less than 5.1 mmol/L or factors contributing to potentially false report of serum potassium were excluded. The primary outcome was the average change in potassium from baseline to 24 hours following potassium binder administration. Secondary outcomes compared changes to potassium from baseline to various time periods after administration, presence of electrolyte changes, and documentation of serious adverse events. Results: A total of 246 patients were included, with 128 receiving SZC and 118 receiving SPS. Mean change in serum potassium (mmol/L) at 24 hours was not significant between binders (−.78 vs −.91; P = .22). Secondary efficacy and safety outcomes were also similar between groups. A total of 5 serious adverse events were reported, occurring only in the SPS group. Conclusion: SZC and SPS have comparable effects in acute potassium reduction, with serious gastrointestinal adverse events documented only in SPS patients. Health systems may consider this data in determining medication formularies or during order set development.