Sodium zirconium cyclosilicate versus sodium polystyrene sulfonate for treatment of hyperkalemia in hemodialysis patients: a randomized clinical trial.

Background: Hyperkalemia is a frequent life-threatening condition in hemodialysis (HD) patients. Data comparing the usage of various K + binders in HD patients is still scarce. This study aimed to compare the efficacy and safety of Sodium zirconium cyclosilicate (SZC) and sodium polystyrene sulfonate (SPS) for treatment of hyperkalemia in HD patients.

Methods: This prospective, double-blinded, randomized multicenter clinical trial enrolled 120 HD patients with predialysis serum potassium > 5 mmol/L. Patients were randomized to receive SZC (5 g, 3 times/wk on non-dialysis days, 15 gm/wk) or SPS (15 g, 3 times/wk on non-dialysis days, 45 gm/wk) for 8 weeks. The change in serum potassium through the 8 weeks of the study was our primary outcome.

Results: Serum potassium significantly decreased in both groups compared to baseline values from the first week till the end of the study with p value of < 0.001 and < 0.001 respectively. Serum K levels in the SZC group were significantly lower (achieved normokalemia after 2 weeks) than K levels in the SPS group (achieved normokalemia after 6 weeks) through the study period (p < 0.001). Rescue therapy for hyperkalemia was less frequent in the SZC group (3.3%) than the SPS group (6.6%) (p = 0.678). Gastrointestinal side effects were non significantly fewer with SZC (5%) compared to SPS (11.6%). However, SPS was less palatable (p < 0.001).

Conclusions: When compared to SPS treatment, SZC was associated with a more rapid and efficacious resolution of hyperkalemia with potentially a better safety profile and palatability among HD patients.

Clinical trials registration: ClinicalTrials.gov Identifier: NCT06029179. First registration date: 9/01/2023.