Infusion of total dose iron versus oral iron supplementation in ambulatory peritoneal dialysis patients: a prospective, cross-over trial.

The efficacy of intermittent, small doses of intravenous iron in hemodialysis patients is well established. But poor peripheral vascular access and frequency of therapy preclude acceptability of this method in peritoneal dialysis (PD) patients. Therefore, despite its marginal efficacy, oral iron remains the common method of iron supplementation in these patients. This prospective, cross-over trial compares infusion of total dose iron (ITDI) and oral iron supplementation in outpatient PD patients. Eleven stable CAPD patients with an hematocrit (Hct) of less than 33%, or a transferrin saturation (TSAT) of less than 30%, or both, were entered into the study. The study design included an oral phase [4 months, ferrous sulfate 325 mg (195 mg elemental iron), three times daily], a "wash-out" phase (1 month, no iron supplementation), and an ITDI phase [4 months, single infusion over 4 hours of 1 g iron dextran mixed in 1/2 normal saline]. Laboratory parameters were monitored monthly, and subcutaneous recombinant human erythropoietin (rHuEPO) doses were adjusted monthly to maintain a hematocrit above 33%. Patients with hyperparathyroidism, aluminum toxicity, and weekly Kt/V below 1.8 were excluded. Nine patients [8 Caucasians, 1 African American; causes of end-stage renal disease (ESRD): hypertension (4 cases), diabetes (3 cases), glomerulonephritis (1 case), and polycystic kidney disease (1 case); mean age: 43.3 +/- 2 years; mean weight: 73.0 +/- 4 kg; duration of ESRD: 28 +/- 13 months] completed the 9-month study. During the oral phase, TSAT rapidly decreased and a higher dose of rHuEPO failed to maintain Hct, a pattern sustained during the "wash-out" phase. During the ITDI phase, TSAT significantly increased and improvement in Hct resulted in a significant lowering of rHuEPO doses. The ITDI therapy was well tolerated. We conclude that ITDI is the preferred method of iron supplementation in outpatient PD patients.