pyrophosphate and ferric-citrate

Management of anemia remains an integral component in the care of patients with chronic kidney disease undergoing hemodialysis. In addition to erythropoiesis-stimulating agents, iron-replacement agents remain a key strategy for anemia treatment in this patient population. Ferric pyrophosphate citrate (FPC), a novel iron-replacement agent, was approved by the US Food and Drug Administration in January 2015 for use in adult patients receiving chronic hemodialysis (HD). This iron product is administered to patients on HD via the dialysate. The recently published, multicenter, randomized, placebo-controlled, phase 3 clinical trials found FPC to maintain hemoglobin level and iron balance in patients undergoing chronic HD. The mean hemoglobin level in these phase 3 clinical studies was maintained from baseline to the end of the treatment in the dialysate iron (FPC-treated) group, however, it decreased by 0.4 g/dL in the control group (P < 0.001). Adverse and serious adverse events were similar in both groups. Another recent study showed a significant reduction in the prescribed ESA dose at the end of treatment in the FPC-treated group compared with placebo. These studies have shown that FPC administered via the dialysate is efficacious and apparently well tolerated. In this article, in addition to reviewing the clinical studies evaluating the efficacy and safety of FPC, we propose a protocol for iron management in HD centers where FPC is to be used.

Topics: Anemia, Iron-Deficiency; Dialysis Solutions; Diphosphates; Ferric Compounds; Hematinics; Humans; Iron; Kidney Failure, Chronic; Renal Dialysis

Administration of ferric pyrophosphate citrate (FPC, Triferic™) via hemodialysate may allow replacement of ongoing uremic and hemodialysis-related iron losses. FPC donates iron directly to transferrin, bypassing the reticuloendothelial system and avoiding iron sequestration.. Two identical Phase 3, randomized, placebo-controlled trials (CRUISE 1 and 2) were conducted in 599 iron-replete chronic hemodialysis patients. Patients were dialyzed with dialysate containing 2 µM FPC-iron or standard dialysate (placebo) for up to 48 weeks. Oral or intravenous iron supplementation was prohibited, and doses of erythropoiesis-stimulating agents were held constant. The primary efficacy end point was the change in hemoglobin (Hgb) concentration from baseline to end of treatment (EoT). Secondary end points included reticulocyte hemoglobin content (CHr) and serum ferritin.. In both trials, Hgb concentration was maintained from baseline to EoT in the FPC group but decreased by 0.4 g/dL in the placebo group (P < 0.001, combined results; 95% confidence interval [CI] 0.2-0.6). Placebo treatment resulted in significantly larger mean decreases from baseline in CHr (-0.9 pg versus -0.4 pg, P < 0.001) and serum ferritin (-133.1 µg/L versus -69.7 µg/L, P < 0.001) than FPC treatment. The proportions of patients with adverse and serious adverse events were similar in both treatment groups.. FPC delivered via dialysate during hemodialysis replaces iron losses, maintains Hgb concentrations, does not increase iron stores and exhibits a safety profile similar to placebo. FPC administered by hemodialysis via dialysate represents a paradigm shift in delivering maintenance iron therapy to hemodialysis patients.

Topics: Administration, Intravenous; Anemia, Iron-Deficiency; Dialysis Solutions; Dietary Supplements; Diphosphates; Female; Ferric Compounds; Hematinics; Hemoglobins; Humans; Iron; Male; Middle Aged; Prospective Studies; Renal Dialysis; Single-Blind Method; Treatment Outcome

Although potassium sorbate (PS), ascorbic acid and ferric or ferrous salts (Fe-salts) are used widely in combination as food additives, the strong reactivity of PS and oxidative potency of ascorbic acid in the presence of Fe-salts might form toxic compounds in food during its deposit and distribution. In the present paper, the reaction mixture of PS, ascorbic acid and Fe-salts was evaluated for mutagenicity and DNA-damaging activity by means of the Ames test and rec-assay. Effective lethality was observed in the rec-assay. No mutagenicity was induced in either Salmonella typhimurium strains TA98 (with or without S-9 mix) or TA100 (with S-9 mix). In contrast, a dose-dependent mutagenic effect was obtained when applied to strain TA100 without S-9 mix. The mutagenic activity became stronger increasing with the reaction period. Furthermore, the reaction products obtained in a nitrogen atmosphere did not show any mutagenic and DNA-damaging activity. PS, ascorbic acid and Fe-salts were inactive when they were used separately. Omission of one component from the mixture of PS, ascorbic acid and Fe-salt turned the reaction system inactive. These results demonstrate that ascorbic acid and Fe-salt oxidized PS and the oxidative products caused mutagenicity and DNA-damaging activity.

Topics: Ascorbic Acid; Diphosphates; DNA Damage; Edetic Acid; Ferric Compounds; Ferrous Compounds; Food Preservatives; Iron; Mutagenicity Tests; Ribosomal Proteins; Salmonella typhimurium; Sorbic Acid

One of the most efficient anions in enhancing the ability of desferrioxamine (DFO) to remove iron from transferrin in vitro has been shown to be pyrophosphate (PYP). To evaluate the in vivo effect of PYP in hyperferremic mice, the biodistribution of [59Fe]ferric citrate was studied after the i.p. administration of: 1) only saline in the control animals; 2) an aqueous solution of tetrasodium diphosphate (PYP; 40 gm/2 g of b.wt.); 3) desferral (DFO; 12 mg/20 g of b.wt.); and 4) PYP + DFO at the respective dosages shown above. The radioactivity in each organ, blood, urine and feces was measured and referred to as percentage of the injected dose. PYP administered alone acted as a weaker chelator of iron than DFO. The combined administration of DFO and PYP contributed more than DFO or PYP separately, to the increase of urinary excretion of 59Fe and to the significant decrease of the radioiron concentration in liver (.01 less than P less than .05). The above induced changes are not, however, the additive result of the separate effect of DFO and PYP. That observation would suggest that DFO + PYP combined in a unique treatment, interact with iron through a common reaction pathway and that PYP plays in vivo a synergistic role in that interaction. The kind of iron with which DFO + PYP interacts is then suggested to be the transferrin-bound iron located in extracellular spaces of tissues.

Topics: Animals; Deferoxamine; Diphosphates; Drug Combinations; Ferric Compounds; Iron; Iron Radioisotopes; Mice; Tissue Distribution