A RANDOMIZED CONTROLLED-STUDY OF IRON SUPPLEMENTATION IN PATIENTS TREATED WITH ERYTHROPOIETIN

In view of current uncertainty regarding the optimum route for iron su pplementation in patients receiving recombinant human erythropoietin ( EPO), a prospective randomized controlled study was designed to invest igate this issue. All iron-replete renal failure patients commencing E PO who had a hemoglobin concentration < 8.5 g/dl and an initial serum ferritin level of 100 to 800 mu g/liter were randomized into three gro ups with different iron supplementation: Group 1, i.v. iron dextran 5 ml every 2 weeks; Group 2, oral ferrous sulphate 200 mg tds, Group 3, no iron. All patients were treated with 25 U/kg of EPO thrice weekly s ubcutaneously. The hemoglobin concentration, reticulocyte count, serum ferritin, transferrin saturation, and EPO dose were monitored every t wo weeks for the first four months. Thirty-seven patients entered th; study (12 i.v., 13 oral, 12 no iron). The three groups were equivalent with regard to age, sex and other demographic details. Even allowing for dosage adjustments, the hemoglobin response in the group receiving i.v. iron (7.3 +/- 0.8 to 11.9 +/- 1.2 g/dl) was significantly greate r than that for the other two groups (7.2 +/- 1.1 to 10.2 +/- 1.4 g/dl and 7.3 +/- 0.8 to 9.9 +/- 1.6 g/dl for Groups 2 and 3, respectively; P < 0.005 for both groups vs. Group 1 at 16 weeks). There was no diff erence between the groups supplemented with oral iron and no iron. Ser um ferritin levels remained constant in those receiving i.v. iron (345 +/- 273 to 359 +/- 140 mu g/liter), in contrast to the other two grou ps in which ferritin levels fell significantly (309 +/- 218 to 116 +/- 87 mu g/liter and 455 +/- 206 to 131 +/- 121 mu g/liter for Groups 2 and 3, respectively; P < 0.0005 for Group 1 vs. Group 2, and P < 0.005 for Group 1 vs. Group 3 at 16 weeks). Dosage requirements of EPO were less in Group 1 (1202 +/- 229 U/kg/16 weeks) than in Group 2 (1294 +/ - 314 U/kg/16 weeks) or Group 3 (1475 +/- 311 U/kg/16 weeks; P < 0.05 vs. Group 1). The results of this study suggest that, even in iron-rep lete patients, those supplemented with i.v. iron have an enhanced hemo globin response to EPO with better maintenance of iron stores and lowe r dosage requirements of EPO, compared with those patients receiving o ral iron and no iron supplementation.