Long-term CaCO₃ treatment of chronic hemodialysis patients: An attempt to prevent aluminum osteopathy

Long-term CaCO₃ treatment of chronic hemodialysis patients was studied. Single doses of CaCO₃ were given to 25 patients, 23 of whom had been receiving Al(OH)₃ before the study. When predialysis serum calcium (Ca) rose to >5.5 mEq/L, CaCO₃ was reduced and Al(OH)₃ was administered again. Eighteen months later, serum phosphate (P) was well controlled, and predialysis serum P was less than 6.5 mg/dl in 14 patients given CaCO₃ alone. Alkaline phosphatase (ALP) levels significantly decreased, and serum aluminum was remarkably lowered in patients who had discontinued Al(OH)₃. In patients who resumed Al(OH)₃, ALP levels rose after Al(OH)₃ administration. Although levels of c-PTH did not change in CaCO₃ treated patients, six patients with poor control of serum P before the study showed a significant decrease in c-PTH. These data indicate that CaCO₃ is an effective P binder that stops the progression of silent osteopathy, presumably caused by oral intake of Al(OH)₃, and may ameliorate these changes. However, further effort will be necessary to develop means to control serum Ca, because long-term use of CaCO₃ induced hypercalcemia in half the patients.