An introduction to phosphate binders for the treatment of hyperphosphatemia in patients with chronic kidney disease

Chronic kidney disease has the potential to induce sequelae that can have severe and mortal outcomes. In particular, impaired glomerular filtration can cause a hyperphosphatemic state, which, if left unchecked, can lead to secondary hyperparathyroidism, vascular calcification, and renal osteodystrophy. Therapeutic management of hyperphosphatemia must maintain both phosphorus and calcium serum concentrations within the recommended guidelines. The balance of both minerals is regulated by parathyroid hormone; thus, an imbalance of one affects the other. In end-stage renal disease, patients often present with hypocalcemic levels due to the kidneys' inability to generate active vitamin D to promote calcium absorption in the intestine. Absorption of calcium can be increased by the administration of active vitamin D analogues. Minimizing phosphorus intake through a strict dietary regimen, combined with the use of phosphate binders to absorb excess ingested phosphate, can help to maintain serum phosphate levels near the recommended concentration of 5.5 mg/dL. Phosphate-binding compounds have evolved from the original aluminum-based binders pioneered in the 1970s to calcium-based binders such as calcium acetate, and more recently, to the following additions to the nephrologist's armamentarium: sevelamer-a polyhydrochloride polymer, and lanthanum carbonate. One of the top 2 common clinical treatments for hyperphosphatemia, calcium acetate, has an established history of efficacy since the 1980s, and has been shown to be cost effective and well tolerated, as well.