A prospective crossover trial comparing intermittent intravenous and continuous oral iron supplements in peritoneal dialysis patients

Background. Concomitant iron supplementation is required in the great major ity of erythropoietin (Epo)-treated patients with end-stage renal failure. Intravenous (i.v.) iron supplementation has been demonstrated to be superio r to oral iron therapy in Epo-treated haemodialysis patients, but comparati ve data in iron-replete peritoneal dialysis (PD) patients are lacking. Methods. A 12-month, prospective, crossover trial comparing oral and i.v. i ron supplementation was conducted in all Princess Alexandra Hospital PD pat ients who were on a stable dose of Epo, had no identifiable cause of impair ed haemopoiesis other than uraemia, and had normal iron stores (transferrin saturation > 20% and serum ferritin 100-500 mg/l). Patients received daily oral iron supplements (210 mg elemental iron per day) for 4 months followe d by intermittent, outpatient i.v. iron infusions (200 mg every 2 months) f or 4 months, followed by a further 4 months of oral iron. Haemoglobin level s and body iron stores were measured monthly. Results. Twenty-eight individuals were entered into the study and 16 patien ts completed 12 months of follow-up. Using repeated-measures analysis of va riance, haemoglobin concentrations increased significantly during the i.v. phase (108 +/-3 to 114 +/-3 g/l) compared with each of the oral phases (109 +/-3 to 108 +/-3 g/l and 114 +/-3 to 107 +/-4 g/l, P <0.05). Similar patte rns were seen for both percentage transferrin saturation (23.8 +/-2.3 to 30 .8 +/-3.0%, 24.8 +/-2.1 to 23.8 +/-2.3%, and 30.8 +/-3.0 to 26.8 +/-2.1%, r espectively, P <0.05) and ferritin (385 +/- 47 to 544 +/- 103 mg/l, 317 +/- 46 to 385 +/- 47 mg/l, 544 +/- 103 to 463 +/- 50 mg/l, respectively, P=0.1 0). No significant changes in Epo dosages were observed throughout the stud y. I.v. iron supplementation was associated with a much lower incidence of gastrointestinal disturbances (11 vs 46%, P <0.05), but exceeded the cost o f oral iron treatment by 6.5-fold. Conclusions. Two-monthly i.v. iron infusions represent a practical alternat ive to oral iron and can be safely administered to PD patients in an outpat ient setting. Compared with daily oral therapy, 2-monthly i.v. iron supplem entation in PD patients was better tolerated and resulted in superior haemo globin levels and body iron stores.