Therapeutic agents for hyperphosphatemia

Abstract

Hyperphosphatemia is one of the major causes of secondary hyperparathyroidism (II degrees HPT) in dialysis patients. Aluminum (Al) hydroxide was commonly used as a phosphate binder in Japan until the beginning of the 1990's, when it was replaced by calcium(Ca) compounds to eliminate undesirable side effects. Although Ca compounds are effective phosphate binders, the concomitant use of vitamin D derivatives can often result in hypercalcemia. For the reason, physicians today have been requesting phosphate binders that contain neither Al nor Ca. In this paper, we introduce several such phosphate binders. Sevelamer hydrocholoride (SH) is a new phosphate binder that contains neither Al nor Ca, and is not absorbed from the gastrointestinal tract. Several short-term clinical studies have established that SH is as efficient as calcium carbonate at lowering serum phosphorus (P) levels, with significant improvement in the Ca x P product and lipids metabolism. Furthermore, a long-term (52 weeks) study revealed that SH attenuated the progression of coronary and aortic calcification in hemodialysis (HD) patients. SH is considered a highly effective phosphate binder in protecting against the progression of II degrees HPT and cardiovascular death in HD patients.