Iron management during recombinant human erythropoietin therapy

Treatment with recombinant human erythropoietin (r-HuEPO; EPOGEN [epoetin alfa], AMGEN Inc, Thousand Oaks, CA) rapidly corrects the anemia associated with end-stage renal disease during the acute phase of therapy and supports hematocrit levels throughout the maintenance phase. However, during the acute phase of therapy, iron deficiency will develop in most patients; it is therefore initially essential to monitor body iron stores monthly. A plasma ferritin level of less than 30 ng/mL or a transferrin saturation level of less than 20% confirms the diagnosis of iron deficiency. Microcytic, hypochromic red cell morphology appears only after prolonged iron deficiency due to inadequate monitoring and insufficient iron supplementation; alternatively, microcytosis in the presence of adequate iron stores suggests aluminum toxicity. In all patients except those with transfusional iron overload, prophylactic supplementation with ferrous sulfate (325 mg up to three times daily) is recommended. When oral supplements, which are poorly tolerated at high doses, are insufficient to meet the extraordinary needs resulting from r-HuEPO-induced erythropoiesis, intravenous iron dextran (500 to 1,000 mg administered in five to ten doses) may be required. During the maintenance phase of therapy, it may be necessary to continue iron supplementation to counteract ongoing loss of iron associated with blood loss through dialyzers and gastrointestinal bleeding. At the other extreme of iron balance, iron overload in transfusion-dependent patients, recent studies suggest that the ability of r-HuEPO to mobilize iron stores can be harnessed with therapeutic phlebotomy to reverse transfusional iron overload.