Comparison of Patiromer to Sodium Polystyrene Sulfonate in Acute Hyperkalemia

Background: Patiromer and sodium polystyrene sulfonate (SPS) are cation-exchangers approved for the treatment of chronic hyperkalemia. Data regarding their efficacy acutely is lacking. Despite this, both drugs are frequently used in the emergent setting. Objective: The purpose of this study was to compare the potassium reduction of patiromer to SPS within 6 to 24 hours following a single dose. Methods: This retrospective quality improvement project included hyperkalemic patients receiving 1 dose of patiromer or SPS and had a second potassium level drawn in 6 to 24 hours. Doses of 8.4 g of patiromer and 15 g of SPS were considered "low dose" while 16.8 g of patiromer and 30 g of SPS were considered "high dose." The presence of a dose-response relationship was assessed through a linear regression analysis. Results: Mean (SD) potassium reduction was higher in SPS than patiromer [0.76 (0.63) mEq/L vs 0.32 (0.65) mEq/L, (P = .001)]. A dose response relationship was not demonstrated in low versus high dose groups [-0.21 (0.14), P = .13] and CKD, ESRD, and renal transplant patients when compared to patients with normal renal function [0.11 (0.17), P = .51, -0.07 (0.19), P = -0.07 (0.19), P = .73, and -0.10 (0.22), P = .65]. Conclusions: This study suggests a clinically significant reduction in potassium with SPS compared to patiromer. Although SPS was successful in demonstrating this outcome, due to well-documented adverse reactions in the literature and a time to onset of 6 hours, it cannot be recommended for use in acute hyperkalemia either.