Effects of switching from sevelamer hydrochloride to bixalomer on laboratory parameters in hemodialysis patients.

In Japan, the clinical use of bixalomer, a new polymer preparation like sevelamer hydrochloride, became possible from 2012. In our study, in order to investigate the clinical characteristics of this new phosphorus (P) binder, bixalomer in a clinical practice, for 18 cases of hemodialysis patients at our hospital being treated with sevelamer hydrochloride, we switched the P binder to bixalomer, and compared the laboratory parameters before and after switching. Subjects used for analysis were nine cases in which it was possible to use bixalomer continuously for 10 months. The laboratory parameters measured were the concentrations of serum P, corrected calcium (Ca), whole parathyroid hormone (PTH), albumin and alkaline phosphatase (ALP) as indicators of mineral and bone disorder, and serum high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) as indicators of lipid metabolism. Regarding the results after switching to bixalomer and starting treatment using the same dosage as the dosage previously used for sevelamer hydrochloride, there were many cases that showed increasing P concentrations that required increasing the dosage of bixalomer, the dosage after switching was increased significantly (P=0.002). In the comparison of laboratory parameters before and after switching, the concentrations of serum P and albumin decreased significantly (P=0.035 and 0.033). From these results, it was considered that the decreases in serum P concentrations were due not only to the effects of bixalomer, but that suppression of food intake by patients was another reason. There were no significant changes in corrected Ca, whole PTH or ALP. In addition, after changing the P binder, serum HDL-C concentration decreased significantly (P=0.015) and LDL-C increased significantly (P<0.001), and serum TG concentration showed no significant changes. This indicated that the beneficial effects of bixalomer on lipid metabolism may be less than those of sevelamer hydrochloride.