Stabilized polynuclear iron hydroxide is an efficient oral phosphate binder in uraemic patients

Background. There is a continuing need for non-aluminium and non-calcium-co ntaining oral phosphate binders. A novel product, i.e. stabilized polynucle ar iron hydroxide, has experimentaly been shown to be an effective phosphat e binder. The purpose of the study was to test the efficacy and tolerabilit y of the compound in hyperphosphataemic patients with stable preterminal re nal failure. Methods, In an open uncontrolled study we examined a total of 13 patients w ith stable preterminal renal failure (median serum-creatinine 5.4 mg/dl, ra nge 4.2-7.3 mg/dl) and hyperphosphataemia (median fasting plasma-Pi 2.2 mmo l/l, range 1.95-3.0 mmol/l). Patients were given dietary advise to maintain a constant intake of phosphate and this was verified by measuring urinary Pi excretion. After 2 weeks on no oral phosphate binders, patients were giv en daily 3 x 2.5 g stabilized polynuclear iron hydroxide with meals for 4 w eeks. In a blinded fashion plasma-Pi and urinary-Pi as well as 1,84 i-PTH, vitamin D metabolites, serum-iron and ferritin were measured in a central l aboratory. Results. Compared to baseline (no oral phosphate binders), the median per c ent decrease of fasting plasma-Pi at day 14 was 20% (7.2-41%) (P<0.001 by W ilcoxon test) and the median per cent decrease of urinary P excretion was 3 7% (9.6-56.6%) (P<0.0003 by Wilcoxon test for paired differences). Ferritin levels did not differ significantly during the study. Apart from a certain laxative action and black discolouration of the faeces, no side effects we re noted in this shortterm study. Conclusion. Stabilized polynuclear iron hydroxide is a promising, efficaceo us and well tolerated phosphate binder.