A comparison of the calcium-free phosphate binder sevelamer hydrochloride with calcium acetate in the treatment of hyperphosphatemia in hemodialysis patients

Current phosphate binders used in hemodialysis patients include calcium-bas ed binders that result in frequent hypercalcemia and aluminum-based binders that result in total body aluminum accumulation over time. This investigat ion describes the use of a calcium- and aluminum-free phosphate-binding pol ymer in hemodialysis patients and compares it with a standard calcium-based phosphate binder. An open-label, randomized, crossover study was performed to evaluate the safety and effectiveness of sevelamer hydrochloride in con trolling hyperphosphatemia in hemodialysis patients. After a 2-week phospha te binder washout period, stable hemodialysis patients were administered ei ther sevelamer or calcium acetate, and the dosages were titrated upward to achieve improved phosphate control over an 8-week period. After a 2-week wa shout period, patients crossed over to the alternate agent for 8 weeks. Eig hty-four patients from eight centers participated in the study. There was a similar decrease in serum phosphate values over the course of the study wi th both sevelamer (-2.0 +/- 2.3 mg/dL) and calcium acetate (-2.1 +/- 1.9 mg /dL). Twenty-two percent of patients developed a serum calcium greater than 11.0 mg/dL while receiving calcium acetate, versus 5% of patients receivin g sevelamer (P < 0.01). The incidence of hypercalcemia for sevelamer was no t different from the incidence of hypercalcemia during the washout period. Patients treated with sevelamer also sustained a 24% mean decrease in serum low density lipoprotein cholesterol levels, Sevelamer was effective in con trolling hyperphosphatemia without resulting in an increase in the incidenc e of hypercalcemia seen with calcium acetate. This agent appears quite effe ctive in the treatment of hyperphosphatemia in hemodialysis patients, and i ts usage may be advantageous in the treatment of dialysis patients. (C) 199 9 by the National Kidney Foundation, Inc.