Patiromer in Patients With Kidney Disease and Hyperkalemia Receiving RAAS Inhibitors | Journal Scan

Study Questions:

What is the safety and efficacy of patiromer (a nonabsorbed polymer that binds potassium in exchange for calcium, primarily in the distal colon) in patients with chronic kidney disease who have hyperkalemia while receiving at least one renin-angiotensin-aldosterone system (RAAS) inhibitor?


This was a two-phase study: a 4-week single-group, single-blind initial treatment phase and an 8-week placebo-controlled, single-blind, randomized withdrawal phase. In the initial treatment phase, those with serum potassium levels of 5.1 to <6.5 mmol/L received patiromer. Those with a serum potassium within normal range (3.8 to <5.1 mmol/L) at the end of the initial treatment phase were eligible for the randomized withdrawal phase. In the second phase, participants were randomly assigned to continue receiving patiromer or placebo. The primary efficacy endpoint was the between-group difference in the median change in the serum potassium level over the first 4 weeks of that phase.


A total of 107 patients participated in the second phase of the study and were randomly assigned to continue patiromer treatment (55 patients) or to switch to placebo (52 patients). A recurrence of hyperkalemia occurred in 60% (95% confidence interval [CI], 47-74%) of the patients in the placebo group, compared to only 15% (95% CI, 6-24%) in the patiromer group (p < 0.001). Mild-to-moderate constipation was the most common side effect, and occurred in 11% of patients. Approximately 5% of patients in the patiromer group and 2% of those in the placebo group developed hypokalemia (serum potassium <3.8 mmol/L).


In patients with chronic kidney disease and hyperkalemia while receiving therapy with at least one RAAS inhibitor, patiromer was associated with a decrease in serum potassium levels, compared to placebo.


This is an important multicenter prospective trial that draws attention to the safety and efficacy of patiromer, a nonabsorbed potassium binder. While the authors demonstrated the efficacy of patiromer in reducing recurrent hyperkalemia, additional data are certainly needed to inform the long-term safety of this agent and establish its efficacy on clinical endpoints.

Clinical Topics: Heart Failure and Cardiomyopathies

Keywords: Hyperkalemia, Hypokalemia, Polymers, Potassium, Prospective Studies, Recurrence, Renal Insufficiency, Chronic, Renin-Angiotensin System, Single-Blind Method

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