Hypophosphatemic effect of 1% amino acid dialysis solution

Orally administered essential amino acids and their nitrogen free analogues have been shown to ameliorate hyperphosphatemia in uremic patients. The aim of the study was to assess the effect on serum phosphate and ionized calcium of a mixture of non-essential and essential amino acids, administered intra peritoneally as a 1% solution to a group of uremic patients who had been on continuous ambulatory peritoneal dialysis (CAPD) for at least three months. Serum phosphate and ionized calcium were measured at fortnightly intervals during the study period which lasted 16 weeks. All patients performed four 2 liter exchanges with dextrose dialysis solution for the first 4 weeks. Two of the four exchanges were then replaced by a 1% amino acid (AA) dialysis solution for a period of 8 weeks after which all patients reverted to their original regimen. Serum phosphate and calcium were measured fortnightly for a further 4 weeks. Serum phosphate fell significantly after introduction of the AA dialysis solution despite unchanged dietary protein and phosphate intake and no increase in the dose of oral phosphate binders taken by 2 of the 7 patients. Serum ionized calcium remained unchanged during the study period.