Moderator's view: Phosphate binders in chronic kidney disease patients: a clear ‘No’ at the moment, but stay tuned

Abstract

Particularly because the risk of harm cannot be safely excluded, the use of phosphate binders in chronic kidney disease (CKD) patients demands caution. Yet, the clinical inertia concerning phosphate burden is unjustified. Inorganic, phosphate esters added to preserve food represent an important component of dietary phosphate load. These compounds are easily absorbable and have a measurable effect on serum phosphate, and therefore their use should be avoided in CKD patients. The ongoing CKD Optimal management with Binders and NicotinamidE (COMBINE) study, applying chelation by phosphate binders and intestinal Na-P channel blockade by nicotinamide, will establish whether this combination may effectively reduce serum phosphate and fibroblast growth factor 23 in pre-dialysis CKD patients and produce improvements in surrogate measures of cardiovascular and renal damages. On the other hand, the ANSWER study will ascertain whether phosphate reduction by sevelamer carbonate may have an antiproteinuric effect in CKD patients with residual proteinuria despite effective blockade of the renin-angiotensin system. At this stage of knowledge, the use of phosphate binders in pre-dialysis CKD patients cannot be recommended. Ongoing studies will tell us whether the application of these drugs may have beneficial health effects in CKD patients at the pre-dialysis stage.