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 24 h post-30 g oral SPS suspended in 33% sorbitol. Secondary outcomes included decrease in potassium within 24 h 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 24 h 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 24 h 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 14-16 h 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 24 h 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.

Keywords: chronic kidney disease; end-stage renal disease; hyperkalemia; sodium polystyrene sulfonate.

FIGURE 1

Patient screening. eGFR, estimated glomerular filtration rate; K⁺, potassium.

FIGURE 2

Efficacy. Serum potassium pre- and post-SPS therapy by dose. Data are presented as box-and-whisker plots, in which the horizontal lines within the rectangles indicate the 50th percentile. The top and bottom of the rectangles indicate the 75th and 25th percentiles, respectively. The lines above and below the rectangles indicate Q1 or Q3 + (1.5 × IQR), respectively.