Haemodialysis patients frequently have simultaneous hypercalcemia and hyperphosphatemia, posing a therapeutic dilemma for the traditional calcium--and aluminum--based binders. RenaGel (sevelamer hydrochloride) is an effective phosphate binder without changes in serum calcium or aluminum levels. However being an expensive medication it is currently used mainly for patients with moderate to severe secondary hyperparathyroidism. However most of the previous studies have not included patients with severe secondary hyperparathyroidism.