Management of hyperkalemia in chronic heart failure using sodium zirconium cyclosilicate

Background Sodium zirconium cyclosilicate (SZC), a newly-developed selective potassium binder, has been clinically available to treat hyperkalemia. SZC might be a promising option to manage hyperkalemia, particularly in patients with heart failure, who often require potassium-sparing medications. However, the optimal initial dose of SZC therapy at a loading dose (30 g per day for the initial 2 days) versus a maintenance dose (5 g per day) remains unknown. Methods Consecutive patients with heart failure and hyperkalemia who received 2-day SZC therapy were retrospectively included. Safety and efficacy of SZC therapy were compared between the two strategies (maintenance versus loading). Results We had 16 patients (76 years old, 11 men) who received 2-day SZC therapy (4 maintenance dose group and 12 loading dose group). Serum potassium decreased 0.7 mEqL/L by 2-day maintenance dose therapy and 1.3 mEq/L by 2-day loading dose therapy. Following 2-day SZC therapy, 25% of patients had hypokalemia, which was defined as serum potassium <4.0 mEq/L. Baseline lower serum potassium level was associated with the post-SZC hypokalemia. Conclusions SZC immediately decreases approximately 1.0 mEq/L of serum potassium in patients with heart failure and hyperkalemia. However, caution should be exercised when utilizing SZC at a loading dose specifically in those with mild hyperkalemia to prevent iatrogenic hypokalemia.