WASHINGTON—Patiromer, a medication that binds potassium in the gastrointestinal tract, is equally effective in patients with varying degrees of hyperkalemia, according to findings presented at the American Society of Nephrology’s 2019 Kidney Week meeting.

Regardless of the severity of baseline hyperkalemia, patiromer treatment decreased serum potassium levels into the target range of 3.8 to 5.0 mEq/L in the vast majority of patients, Matthew R. Weir, MD, of the University of Maryland School of Medicine in Baltimore, and colleagues reported in a poster presentation.

Dr Weir and his collaborators conducted a post-hoc analysis of pooled data from 623 hyperkalemic patients during the first 4 weeks of treatment in the AMETHYST-DN, OPAL-HK, and TOURMALINE trials. Patients in the AMETHYST-DN and OPAL-HK trials had to have an estimated glomerular filtration rate (eGFR) of 15 to 59 mL/min/1.73 m2.

Of the 623 patients, 53 had serum potassium levels of 6.0 mEq/L or higher and 570 had levels below 6.0 mEq/L. The mean eGFR in these patients was 33.0 and 40.2 mL/min/1.73 m2, respectively. More than 90% of patients in both groups were taking renin-angiotensin-aldosterone system inhibitors, which are known to increase the risk of hyperkalemia, defined as serum potassium levels above 5.0 mEq/L. The median daily dose of patiromer was 18.5 grams per day in patients with baseline serum potassium levels of 6.0 mEq/L or higher and 16.5 grams per day in patients with baseline levels below 6.0 mEq/L. Their analyses looked at data from the first 4 weeks of treatment.

The proportion of patients achieving serum potassium levels in the target range was 92.5% among patients with baseline levels of 6.0 mEq/L or higher and 96.8% among those with baseline levels below 6.0 mEq/L.

Patiromer was generally well tolerated. At least 1 adverse event (AE) occurred in 43% and 31% of patients with serum potassium levels of 6.0 mEq/L or higher and below 6.0 mEq/L, respectively, according to the investigators. Patiromer-related AEs occurred in 19% and 13% of patients, and AEs leading to patiromer discontinuation occurred in 2% and 4% of patients, respectively.

The most common AE was constipation, which occurred 13.2% of patients with baseline serum potassium levels of 6.0 mEq/L or higher 4.9% of those with baseline levels below 6.0 mEq/L. Diarrhea was the next most common AE, occurring in 3.8% and 2.8% of patients, respectively.

Reference

Weir MR, Mayo MR, Yuan J, et al. Efficacy and safety of patiromer by baseline potassium level <6.0 versus ≥6.0 mEq/L: Pooled results of 3 studies. Presented at the American Society of Nephrology’s 2019 Kidney Week meeting held November 5-10 in Washington, DC. Poster FR-254.