Substitution of aluminium hydroxide by high doses of calcium carbonate in patients on chronic haemodialysis: disappearance of hyperaluminaemia and equal control of hyperparathyroidism.

Al(OH)3 was discontinued in 26 patients on chronic haemodialysis as well as vitamin D metabolites in eight. Oral CaCO3 was progressively increased from 4 +/- 3 to 10 +/- 5g/d to keep plasma PO4 less than 6.0mg/dl and P Ca less than 10.5mg/dl. This treatment had to be discontinued in three cases because of diarrhoea and/or uncontrolled hyperphosphataemia. In the remaining patients the control of hyperphosphataemia and of PTH values was as good or even better. Hyperaluminaemia disappeared in most patients demonstrating the role of oral Al(OH)3 in the induction of hyperaluminaemia. Because of frequent transient hypercalcaemia and of the occurrence of vascular calcification in two patients, high doses of CaCO3 after discontinuation of Al(OH)3 are advised only in cases of hyperaluminaemia.