Both patiromer and sodium polystyrene sulfonate (SPS) reduce serum potassium levels in patients receiving hemodialysis, a new study concludes.
Investigators conducted a randomized crossover trial of 48 patients with serum potassium values of 5.0 to 6.4 mmol/L prior to dialysis sessions. Each patient received SPS 15 g before every meal or patiromer 16.8 g once daily on non-dialysis days for 4 weeks with a 2-week washout period in between interventions.
Mean weekly serum potassium values were significantly lower with patiromer (5.00 mmol/L) and SPS (4.55 mmol/L) treatment compared with the washout period (5.17 mmol/L), David A Jaques, MD, Geneva University Hospitals in Switzerland, and colleagues reported in Clinical Kidney Journal. Greater potassium reduction occurred with SPS compared with patiromer at the specified doses: 0.62 vs 0.17 mmol/L, respectively. Using hyperkalemia thresholds of 5.1 and 5.5 mmol/L, hyperkalemia prevalence was 22% and 12% with SPS treatment, respectively, compared with 44% and 17% with patiromer treatment.
Whether different drug dosing or dose titration influences results still needs to be tested, the investigators pointed out.
The higher efficacy of SPS was balanced by lower tolerability. Patients skipped a significantly greater proportion of SPS than patiromer doses (10.8% vs 2.4%). Tolerability score also was significantly lower with SPS than patiromer (6.0 vs 6.9). Gastrointestinal side effects occurred during 25.4% of the study weeks, but did not differ significantly between treatment groups.
The investigators observed differences in electrolyte profiles after SPS and patiromer treatment for hyperkalemia. In addition to potassium, SPS binds calcium and patiromer binds magnesium in the gastrointestinal tract.
“Given the importance of K+ control on cardiovascular outcomes in [hemodialysis] patients, larger randomized controlled trial studies should be conducted in order to confirm our findings and determine whether they would impact clinical outcomes,” Dr Jaques’ team concluded.
Jaques DA, Stucker F, Ernandez T, et al. Comparative efficacy of patiromer and sodium polystyrene sulfonate on potassium levels in chronic haemodialysis patients: a randomized crossover trial. Clin Kidney J. 15(10):1908-1914. doi:10.1093/ckj/sfac129