Effectiveness of calcium acetate as a phosphate binder in patients undergoing continuous ambulatory peritoneal dialysis.

We compared the effectiveness of calcium acetate as a phosphate binder with that of calcium carbonate by substituting one for the other in patients undergoing continuous ambulatory peritoneal dialysis. Twenty patients who had been receiving calcium carbonate as a phosphate binder were instead given calcium acetate, initially with two thirds of the previous dose of elemental calcium. The calcium acetate dose was adjusted to achieve adequate calcium-phosphate balance; 65.6% of the previous dose of elemental calcium in calcium carbonate was required. Eighteen of the 20 patients completed the 3-month study. There were no significant differences in the pre-study and study levels of serum phosphate (1.81plus minus0.04 [SEM] versus 1.89plus minus0.06 mmol/L), corrected serum calcium (2.54plus minus0.04 versus 2.57plus minus0.03 mmol/L), calcium phosphate product (4.60plus minus0.15 versus 4.87plus minus0.18), serum alkaline phosphatase (64.75plus minus4.17 versus 69.94plus minus3.77 U/L), and serum parathyroid hormone (122plus minus31 versus 124plus minus27 ng/L). Three patients developed a total of five episodes of hypercalcaemia (corrected calcium level greater-than-or-equal2.85 mmol/L) and four other patients developed gastrointestinal upset. Calcium acetate can thus achieve similar phosphate control to calcium carbonate, using 65.6% of the dose of elemental calcium in calcium carbonate; however, its clinical superiority was not demonstrated in this study.