A comparison of calcium-based phosphorus binders for patients with chronic kidney disease

Abstract

Hyperphosphatemia in patients with end-stage renal disease (ESRD) is associated with secondary hyperparathyroidism and renal osteodystrophy, and is independently associated with an increased risk of mortality. Therefore, tight control of serum phosphorus is considered essential in these patients. Ideally, the best phosphorus binder would be inexpensive, nontoxic, well tolerated, and potent. Currently, calcium-based binders are generally considered first-line agents for the treatment of hyperphosphatemia in ESRD. However, excessive calcium absorption may produce hypercalcemia and possibly soft-tissue and vascular deposition. Calcium carbonate is a widely used effective, inexpensive, over-the-counter phosphate binder. Calcium acetate is an alternative phosphorus binder that is a more soluble and efficient phosphate binder. Equimolar doses of calcium acetate bind twice as much phosphorus as calcium carbonate. As a result, phosphorus binding can be achieved with a lower dose of calcium. The NKF/K-DOQI guidelines state that the total dose of elemental calcium provided by calcium-based phosphate binders should not exceed 1,500 mg/day. Calcium acetate more readily permits optimal phosphorus binding within these guidelines. This review focuses on calcium binders.