Hyperkalaemia (HK) is common in the emergency department (ED) and can cause life-threatening arrhythmias. Patiromer is a potassium binder whose role in acute HK management is uncertain; therefore, we investigated the efficacy and safety of patiromer as an adjunct to the standard of care treatment of HK in the ED.

A prospective, randomised, double-blind, placebo-controlled study.

16 ED sites across the USA.

Patients aged ≥18 years treated at a participating ED who were found to have serum potassium ≥5.8 mEq/L.

Participants were randomised 1:1 to standard combination therapy (25 g intravenous dextrose, 5 units intravenous insulin and 10 mg albuterol) with either patiromer or placebo. The initial dose was given within 1 hour of the potassium result, and the second dose 24 hours later.

The primary endpoint was net clinical benefit (NCB) at 6 hours, defined as the change in number of potassium-lowering interventions minus change in serum potassium. Adverse events (AEs) were also recorded.

The study was terminated early and did not reach the prespecified sample size. Overall, 111 patients (53 patiromer and 58 placebo) were analysed. Mean (SD) age was 61.34 (15.21) years, 34% were female, 48% white and 22.5% received chronic haemodialysis. Mean baseline potassium was 6.5 mmol/L. NCB at 6 hours was similar between patiromer and placebo (–0.6 vs –0.4; p=0.44). Potassium levels at 2, 4 and 6 hours were similar between the groups (5.50 vs 5.70, 5.45 vs 5.65, 5.50 vs 5.60; patiromer and placebo (all p>0.05)). The number of interventions per patient was similar (p>0.05) between groups at each time point. The proportion of patients experiencing AEs was not significant between the patiromer and placebo groups (16.98% vs 32.76%; p=0.08).

No differences in efficacy were reported in this study, which was underpowered to detect statistical efficacy of patiromer over placebo.

NCT04443608.