Efficacy and safety of calcium polystyrene sulphonate and sodium zirconium cyclosilicate as potassium binders for chronic hyperkalemia in hemodialysis patients: A prospective study

Sodium zirconium cyclosilicate (SZC) and calcium polystyrene sulfonate (CPS) are indicated for treating hyperkalemia in chronic renal disease. Individuals undergoing maintenance hemodialysis (HD) are at significantly increased risk of developing hyperkalemia, clinically defined as serum potassium concentrations of > 5.0 mmol/L. The objective of this study was the evaluation and comparison of the efficacy and safety of two potassium binders (SZC and CPS) in HD patients with hyperkalemia. This research utilized a prospective non-randomized controlled clinical trial design. Patients with chronic hyperkalemia were enrolled at a tertiary care hospital in China from September 2021 to May 2022. HD patients received SZC (5 g) or CPS (5 g) once daily, later adjusted to 10 g. Serum potassium levels were quantified at a specified timepoint at 0, 2, 4, 8, and 12 weeks. The mean serum K+ levels for SZC- and CPS-treated participants were 5.93 ± 0.46 and 5.88 ± 0.54 mmol/L, respectively, at baseline (p = 0.683) and 4.94 ± 0.44 vs. 5.12 ± 0.49 mmol/L respectively after 12 weeks (p = 0.017). A serum potassium concentration of less than 5.3 mmol/L was achieved in 81% of treated patients who received SZC treatment over 12 weeks, compared to 65% of those treated with CPS. Additionally, SZC also achieved a higher percentage of patients exhibiting serum potassium levels below 6.0 mmol/L at the 2-week timepoint (28/28 vs. 27/31, p = 0.015). The mean daily doses were 6.8 g for SZC and 7.42 g for CPS, with no serious adverse events attributable to the study drug. SZC demonstrated superior effectiveness in reducing potassium levels and controlling severe hyperkalemia in patients undergoing maintenance HD. It also facilitated more rapid control of serum potassium levels offering an improved long-term management strategy for chronic hyperkalemia.