Can Novel Potassium Binders Liberate People with Chronic Kidney Disease from the Low-Potassium Diet? A Cautionary Tale

Abstract

The advent of new potassium binders provides an important breakthrough in the chronic management of hyperkalemia for people with CKD. In addition to the direct benefits of managing hyperkalemia, many researchers and clinicians view these new medications as a possible means to safely transition patients away from the low-potassium diet to a more healthful eating pattern. In this review, we examine the mechanisms of potassium binders in the context of hyperkalemia risk related to dietary potassium intake in people with CKD. We note that whereas these medications target hyperkalemia caused by potassium bioaccumulation, the primary evidence for restricting dietary potassium is risk of postprandial hyperkalemia. The majority of ingested potassium is absorbed alongside endogenously secreted potassium in the small intestines, but the action of these novel medications is predominantly constrained to the large intestine. As a result and despite their effectiveness in lowering basal potassium levels, it remains unclear whether potassium binders would provide protection against hyperkalemia caused by excessive dietary potassium intake in people with CKD. Until this knowledge gap is bridged, clinicians should consider postprandial hyperkalemia risk when removing restrictions on dietary potassium intake in people with CKD on potassium binders.