Source: Weir MR, et al. N Engl J Med 2015;372:211-221.

Patiromer (PAT) is an oral non-absorbable polymer that works by binding potassium (K+) in exchange for calcium in the distal colon. Currently available oral treatments for hyperkalemia are burdened by GI adverse effects as well as limited efficacy. Hyperkalemia is particularly problematic in chronic kidney disease (CKD), which may be compounded by the need to administer ACE inhibitors or angiotensin II receptor blockers (ARB).

Weir et al performed a clinical trial of PAT in hyperkalemic patients with CKD stage 3 or 4 (eGFR = 15-59) who had been on a stable dose of ACE inhibitors or ARB for at least 4 weeks. Mild hyperkalemia (K+ = 5.1-5.4 mmol/L) was treated with PAT 4.2 g BID, and moderate-severe hyperkalemia (K+ = 5.5-6.4 mmol/L) with PAT 8.4 g BID.

At the end of 4 weeks, 76% of hyperkalemic patients treated with PAT had reached their target K+ of 3.8-5.0 mmol/L. Re-randomization to placebo or PAT for an additional 8 weeks showed that 85% of PAT-treated patients remained normokalemic, whereas 60% of placebo recipients drifted back into hyperkalemia. PAT was well tolerated: 11% of PAT patients experienced mild-moderate constipation.

PAT shows great promise as a new treatment for hyperkalemia.