Phosphate binders and metabolic acidosis in patients undergoing maintenance hemodialysis-sevelamer hydrochloride, calcium carbonate, and bixalomer

Abstract

The serum bicarbonate (HCO 3 -) levels are decreased in chronic hemodialysis (HD) patients treated with sevelamer hydrochloride (SH). We assessed the effects of bixalomer on the chronic metabolic acidosis in these patients. We examined 12 of the 122 consecutive Japanese patients with end-stage renal disease on HD, who orally ingested a dose of SH (≥2250mg), and an arterial blood gas analysis and biochemical analysis were performed before HD. Patients whose serum HCO 3 - levels were under 18mmol/L were changed from SH to the same dose of bixalomer. A total of 12 patients were treated with a large amount of SH. Metabolic acidosis (a serum HCO 3 - level under 18mmol/L) was found in eight patients. These patients were also treated with or without small dose of calcium carbonate (1.2±1.1g). The dose of SH was changed to that of bixalomer. After 1 month, the serum HCO 3 - levels increased from 16.3±1.4 to 19.6±1.7mmol/L (P<0.05). Metabolic acidosis was not observed in four patients (serum HCO 3 - level: 20.3±0.7mmol/L) likely because they were taking 3g of calcium carbonate with SH. In the present study, the development of chronic metabolic acidosis was induced by HCl containing phosphate binders, such as SH, and partially ameliorated by calcium carbonate, then subsequently improved after changing the treatment to bixalomer.