Calcium-Polystyrene Sulfonate Decreases Inter-Dialytic Hyperkalemia in Patients Undergoing Maintenance Hemodialysis: A Prospective, Randomized, Crossover Study.

Hyperkalemia is a life-threatening emergency in maintenance hemodialysis (MHD) patients. This clinical trial investigated the efficacy and safety of calcium-polystyrene sulfonate (Ca-PS) in MHD patients with interdialytic hyperkalemia. A total of 58 hemodialysis patients with hyperkalemia (≥5.5 mol/L) were selected and administered either a 3-week Ca-PS (3 × 5 g/day) or a blank control following the model of a prospective, randomized, crossover clinical trial with a 1-week washout period. All patients were followed up for another 3 weeks for safety evaluations. The primary outcome was the magnitude of the change in serum potassium levels. The secondary outcomes were electrocardiography (ECG) changes and treatment safety (volume overload, electrolyte imbalance). Compared with the control group, Ca-PS treatment significantly reduced serum potassium levels (P <0.01). More patients in the Ca-PS group had lower serum potassium levels than the safety level of <5.5 mmol/L (32% for control vs. 61% for Ca-PS, P <0.01). Peaked T-wave occurred less frequently in patients in the Ca-PS group (13.8% for Ca-PS vs. 31.03% for control, P <0.01). In addition, Ca-PS reduced serum phosphorus levels with no effects on serum levels of calcium and sodium, fluid volume, blood pressure, or interdialytic weight gain. Ca-PS treatment decreases serum levels of potassium and phosphorus in MHD patients with interdialytic hyperkalemia. Ca-PS does not induce volume overload or disrupt electrolyte balance.