Single-dose sodium polystyrene sulfonate for hyperkalemia in chronic kidney disease or end-stage renal disease

Abstract

Background. The use of sodium polystyrene sulfonate (SPS) for the treatment of hyperkalemia lacks sufficient efficacy data in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD); however, use remains widespread. Recent evidence suggests that this population may be at risk for serious gastrointestinal adverse effects with SPS. Methods. We conducted a single-center retrospective cohort study. Adult patients with CKD Stages 4, 5, or ESRD maintained on renal replacement therapy with serum potassium >5 mEq/L and receipt of SPS were screened for inclusion. Our primary outcome was decrease in potassium within 24h post-30 g oral SPS suspended in 33% sorbitol. Secondary outcomes included decrease in potassium within 24h from 15 or 30 g SPS doses and gastrointestinal adverse events. Results. Of 596 records, 114 were included for analysis. At the first serum potassium level within 24h post-30 g oral SPS the median potassium decrease was 0.8 mEq/L [interquartile range (IQR) 0.4-1.1; P<0.001]. At the first potassium level within 24h post-15 or 30 g SPS, the median potassium decrease was 0.7 mEq/L (IQR 0.4-1.0; P<0.001]. Post-SPS potassium levels occurred 14-16h post-SPS. Gastrointestinal side effects occurred within 30 days of SPS in 5% of patients, although only two cases were classified as possibly associated. Conclusions. The use of single-dose SPS monotherapy resulted in a significant decrease in serum potassium levels within 24h in patients with CKD Stage 4, 5, or ESRD. However, it remains unclear if SPS is associated with an increased risk of gastrointestinal injury in this population.