Efficacy and safety of sevelamer. Comparison with calcium carbonate in the treatment of hyperphosphatemia in hemodialysis patients

OBJECTIVE: Current phosphate binders used in hemodialysis patients include calcium-based binders that result in frequent hypercalcemia. The use of a calcium- and aluminum-free phosphate-binding polymer in hemodialysis (sevelamer) disclosed efficacy in the short and long-term studies. However, due to race differences we performed a short-term study on the Saudi hemodialysis patients and compared sevelamer with a standard calcium-based phosphate binder.

METHODS: An open-label, randomized, cross-over study was performed to evaluate the safety and effectiveness of sevelamer hydrochloride in controlling hyperphosphatemia in hemodialysis patients. After a 2-week phosphate binder washout period, stable hemodialysis patients were given either sevelamer or calcium carbonate, and the dosages were titrated to achieve phosphate control over an 8-week period. After a 2-week washout period, patients crossed over to the alternate agent for 8 weeks. Twenty patients from the Dialysis Unit of King Fahd Hospital, Jeddah, Kingdom of Saudi Arabia, were recruited for the study between March 2003 and June 2003.

RESULTS: There was a similar decrease in serum phosphate values over the course of the study with both sevelamer (-3.3 +/-2.2 mg/dL) and calcium carbonate (-3.9 +/-2.8 mg/dL). Fifty-two percent of patients developed serum calcium greater than 2.75 mmol/L (11.0 mg/dL) while receiving calcium carbonate versus 26% of patients receiving sevelamer (p<0.05). The incidence of hypercalcemia for sevelamer was not different from the incidence of hypercalcemia during the washout period. Patients treated with sevelamer also sustained a 13% mean decrease in serum cholesterol levels.

CONCLUSION: Sevelamer was effective in controlling hyperphosphatemia without resulting in an increase in the incidence of hypercalcemia seen with calcium carbonate. This agent appears quite effective in the treatment of hyperphosphatemia in hemodialysis patients, and its usage may be advantageous in the treatment of dialysis patients.