Use of calcium carbonate as a phosphate binder in dialysis patients

Aluminum-containing phosphate (Al-binders) employed to control serum phosphorus in patients with chronic renal failure can be associated with the development of aluminum toxicity. To obviate the need for Al-binders, we examined the effectiveness of CaCO3 as a phosphate binder in 31 hemodialysis and 8 CAPD patients followed for 2 months while receiving Al-binders, and then, for 3-14 months while receiving CaCO3 (5.8 +/- 0.4 g/day). Monthly serum phosphorus averaged 5.4 +/- 0.2 mg/dl with Al-binders and 5.1 +/- 0.3 to 5.7 +/- 0.4 mg/dl with CaCO3 (p = NS). There were 25.2 episodes of hyperphosphatemia (serum phosphorus greater than 6.5 mg/dl) per 100 treatment months with Al-binders and 19.2 episodes/100 treatment months with CaCO3 (p = NS). Plasma aluminum levels, 105 +/- 21 micrograms/l during ingestion of Al-binders, fell to 34 +/- 11 micrograms/l after 8 months of therapy with CaCO3 (p less than 0.01). Monthly serum Ca averaged 9.5 +/- 0.1 mg/dl during Al administration and was 8.9 +/- 0.8 to 10.0 +/- 0.2 mg/dl with CaCO3 (p = NS). Thirty-four episodes of hypercalcemia (serum Ca greater than 11.0 mg/dl) occurred in 14 patients ingesting CaCO3, but hypercalcemia did not occur with ingestion of Al-binders. Al-related bone disease was found on bone biopsy in 11 of 13 patients who developed hypercalcemia, compared to only 5 of the 11 biopsied patients who remained normocalcemic (p less than 0.01 by chi 2 analysis). Other side effects included diarrhea in 1 patient and constipation in 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)