Pharmacology, efficacy and safety of oral phosphate binders

Abstract

The ideal serum level of phosphate in patients on dialysis, and the benefits of controlling levels of phosphate in serum remain unclear despite observational studies that associate phosphate levels with mortality. In the absence of robust data from trials, current guidelines are necessarily based on opinion. Oral phosphate binders are required by the majority of patients on dialysis, and all of these binders can control serum levels of phosphate to similar degrees. Patient preference and adherence to prescribed therapy is at least as important as the efficacy of the prescribed binder. Avoidance of calcium-containing binders has become accepted practice where the alternatives are affordable, but incontrovertible evidence in favor of this approach is lacking. Use of sevelamer and lanthanum avoids calcium loading, but at considerable financial cost and with no reliable patient outcome data to prove their value. Additional approaches to aid control of serum levels of phosphate include blockade of gastrointestinal phosphate absorption and possibly binding of salivary phosphate. Importantly, the role of phosphate control in determining patient outcomes must be quantified, which is likely to require a large randomized, controlled study of two levels of phosphate control. Without such a study we will continue to rely on observational data with all its uncertainties and potential to mislead.

CKD in Elderly Patients Managed without Dialysis

“…Unfortunately, survival of elderly dialysis patients is generally worse than that for most cancers (5)(6)(7). The most common cause of death on dialysis in Australia appears to be withdrawal for psychosocial or progressive medical reasons, particularly for patients aged .65 years (2), suggesting that the initial choice of treatment may have been suboptimal for many patients.…”

Effect of dietary components on renal inorganic phosphate (Pi) excretion induced by a Pi-depleted diet

“…Pi binders are widely used to control hyperphosphatemia in clinical CKD ; however, none of the currently available binders is ideal (39,40). An alternative approach to the use of binders to limit hyperphosphatemia in CKD is to target the Pi intestinal transporter or sensor directly (39).…”

Managing Oral Phosphate Binder Medication Expenditures Within the Medicare Bundled End-Stage Renal Disease Prospective Payment System: Economic Implications for Large U.S. Dialysis Organizations

“…Although calcium-based binders are relatively inexpensive, calcium salts have been associated with an increased risk of hypercalcemia and vascular calcification. 24,25 The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative recommends that the daily calcium intake from phosphate binders should not exceed 1,500 milligrams per day. 4 Patient quality of care may therefore be compromised under such low medication cost scenarios.…”