Patiromer, a potassium binder approved for the treatment of hyperkalemia, enables longer use of spironolactone in patients with chronic kidney disease (CKD) regardless of diabetes status, according to a recent subgroup analysis of the AMBER trial.

The trial included 295 patients with CKD and resistant hypertension despite taking 3 or more antihypertensive drugs. Investigators randomly assigned patients to receive open-label oral spironolactone 25mg once daily and, in double-blind fashion, either patiromer 8.4g once daily or placebo.

In the original AMBER analysis, 66% of patients in the placebo group and 86% in the patiromer group remained on spironolactone at week 12, the primary study endpoint. In the diabetes subgroup, 65.3% of patients receiving placebo remained on spironolactone at week 12 compared with 83.6% receiving patiromer, Rajiv Agarwal, MD, of Indiana University and the Richard L. Roudebush VA Medical Center in Indianapolis, and colleagues reported in the Clinical Journal of the American Society of Nephrology. In the subgroup without diabetes, 67.1% of patients receiving placebo remained on spironolactone at week 12 compared with 87.8% receiving patiromer. Serum potassium levels of 5.5mEq/L or higher occurred in a significantly higher proportion of the placebo group compared with the patiromer group among those with diabetes (72% vs 41%) and those without diabetes (56.6% vs 29.7%).

‘No Surprises’

“There were no surprises here. This was a more granular look at the original study,” Dr Agarwal said.

He also observed, “Patiromer is the only sodium-free potassium binder approved in the United States and may be an agent of choice for patients with resistant hypertension that may be more sensitive to sodium.”

In the current analysis, the subgroup of 150 patients without diabetes included 76 in the placebo arm and 74 in the patiromer arm. The subgroup of 145 patients with diabetes included 72 in the placebo arm and 73 in the patiromer arm.

In patients with diabetes, patiromer’s safety profile was consistent with previous reports. The authors noted that spironolactone is recommended in patients with resistant hypertension, including those with diabetes. Still, there are concerns that spironolactone may increase hyperkalemia risk, thus limiting its use in patients with diabetes.

Adverse events (AEs) occurred in about 60% of patients with diabetes and 61% of placebo recipients, and 60% of patiromer-treated patients. Serious AEs occurred in 3 placebo recipients and 1 patiromer-treated patient.

This article originally appeared on Renal and Urology News