Lanthanum carbonate for hyperphosphatemia in patients on peritoneal dialysis.

♦ Bac kground: T he efficacy of the phosphate b inder lanthanum carbonate has been demonstrated for hemodialysis patients, but no studies have focused on patients undergoing continuous ambulator y per itoneal dialysis (CAPD). We evaluated whether lanthanum carbonate could control phosphate levels in patients on CAPD. ♦ M ethods: In this 48-week open-label prospective study, 28 patients on CAPD with a phosphate level of 6 m g/dL or greater were given lanthanum carbonate titrated from 750 mg to 2250 mg daily to achieve a target serum phosphate level of less than 6 m g/dL. The primary efficacy endpoint was reduction of serum phosphate to less than 6 mg/dL. Serum levels of calcium and parathyroid hormone were also evaluated, as were the Ca×P product and adverse effects. ♦ R esults: From week 4 to the end of the study at week 48, we observed a significant reduction of serum phosphate to 5.25 ± 0.9 7 mg/dL from 6.88 ± 1 .06 mg/dL at study start (p < 0.01). At the end of the study, 78.6% of participants had achieved the target of less than 6 m g/dL. Because no change of serum calcium occurred, the Ca×P product declined significantly during the study. Intact parathyroid hormone declined gradually over the study period, but the change had not reached significance at the end of the study (p = 0.11). The mean final dose of lanthanum carbonate was 946 m g daily. The only adverse effect reported was mild nausea in 1 patient. ♦ Conclusions: Lanthanum carbonate is an effective phosphate binder that can control serum phosphate and Ca×P product in CAPD patients with hyperphosphatemia. Lanthanum carbonate was well tolerated in our population.