Serum potassium response to single-dose sodium zirconium cyclosilicate for the treatment of asymptomatic hyperkalemia in hospitalized patients.

Study objective: To assess the efficacy of single-dose sodium zirconium cyclosilicate (SZC) compared to the FDA approved three times daily (TID) dosing and to single-dose sodium polystyrene sulfonate (SPS) for the management of asymptomatic hyperkalemia in hospitalized patients.

Design: Single-center retrospective chart review.

Setting: University of Florida Health Jacksonville, a 695-bed academic medical center in Jacksonville, FL, between June 15, 2018 and August 15, 2021.

Patients: Three hundred fifty-one adult patients who were admitted to any hospital unit in the specified timeframe and received one of three interventions for asymptomatic hyperkalemia (serum potassium ≥4.7 mmol/L) were included in this study.

Intervention: The interventions compared were single-dose SZC 10 g, SZC 10 g × 3 doses (30 g total) within 24 h, or SPS 15-30 g once.

Measurements and main results: The primary outcome was the proportion of patients achieving normokalemia (K⁺ 3.3-4.6 mmol/L) within 12-30 h of the first study dose. Secondary outcomes included average change in potassium within 12-30 h and 3-54 h from the first dose. The primary outcome was met in 68 patients (58.1%) in the SZC 10 g group, 51 (43.6%) in the SZC 10 g × 3 doses group, and 81 (69.2%) in the SPS 15-30 g group (p < 0.01). The average reduction in potassium in 12-30 h was 0.70 mmol/L, 0.78 mmol/L, and 0.99 mmol/L in the SZC 10 g, SZC 10 g × 3 doses, and SPS 15-30 g groups, respectively (p < 0.01).

Conclusions: SZC 10 g once resulted in more patients achieving normokalemia compared to SZC 10 g × 3 doses but less than SPS (p < 0.01). Single-dose SZC may be a reasonable option to manage asymptomatic hyperkalemia in the hospital setting, but achieving normokalemia with one dose may be less likely in patients with higher baseline potassium concentrations and impaired renal function.