Comparation of the binder phosphorus effect of calcium carbonate vs calcium acetate during chronic renal failure before dialysis

Introduction: The hyperphosphatemia, hypocalcemia and low calcitriol levels are pathogenic factors for secondary hyperparathyroidism in chronic renal failure. The phosphorus control is essential to prevent secondary hyperpara thyroidism. There are not comparatives studies to test the efficacy of cont rol of phosphorus binders in predialysis patients. Aim: To compare the efficacy of calcium carbonate vs calcium acetate as pho sphate binder in predialysis patients. Material and methods: The present study includes 28 patients with chronic r enal failure (mean clearance of creatinine 21 ml/min). Patients were separa ted into two groups: Group 1: (n = 14) received calcium carbonate 2,500 mg/ day (1,000 mg of calcium); Group 2: (n = 14) receives calcium acetate 1,000 mg (254 mg of calcium). Calcium and phosphorus were determined every 4 mon ths; i-PTH, alkaline fosfatase and clearance of creatinine were determined every six months. Results: Both groups were comparable regarding age, renal function, calcium , phosphorus, alkaline fosfatase and i-PTH on basal situation and the end o f study were not different. The serum calcium increased, not significantly in the calcium carbonate gro up (group 1) [from 9.2 to 9.8 mg/dl (p = 0.05)], however it was not modifie d in the calcium acetate group (group 2). The serum phosphorus decreased si gnificantly (p ( 0.05) in both groups, independently of the calcium levels. Alkaline fosfatase and i-PTH not was modified during the study period. Conclusions: 1) Both calcium carbonate and calcium acetate are similarly ef fective as phosphate binder. 2) The carbonate group required four fold grea ter doses of calcium that acetate group. 3) The calcium acetate has less hy percalcemic effect than calcium carbonate.