Iron supplementation in the non-dialysis chronic kidney disease (ND-CKD) patient: oral or intravenous?

Background: The management of iron-deficiency anaemia in patients with non-dialysis chronic kidney disease (ND-CKD) remains controversial, particularly regarding the use of oral versus intravenous iron supplementation. Methods: A PubMed search from 1970 to February 2009 was conducted to identify relevant research articles. Findings: Iron supplementation is advisable for all iron-deficient CKD patients receiving erythropoiesis stimulating agents (ESAs), and intravenous iron may be preferable to oral iron. However, there is also a growing body of data indicating that iron supplementation may avoid or delay the need for ESA therapy in some ND-CKD patients. In each of four randomised trials that included ND-CKD patients without ESA, the haemoglobin response was greater with i.v. versus oral iron. Moreover, some ND-CKD patients who remain anaemic on oral iron may subsequently respond to i.v. iron. Newer preparations (ferric carboxymaltose and ferumoxytol) permit rapid, high-dose administration. In a randomised study, a single 15-minute injection of ferric carboxymaltose, with up to two additional doses as required, resulted in 53.2% of ND-CKD patients achieving >= 1g/dL increase in haemoglobin by day 56 without ESA, compared to 29.9% of patients given oral iron supplements. Two large, randomised, ongoing trials will address the important question of whether i.v. or oral iron supplementation affects the progression of renal dysfunction. While i.v. iron is more costly than oral iron, the cost differential over time may be lower than widely believed, and i.v. therapy avoids the poor absorption, gastrointestinal intolerance and non-compliance associated with oral preparations. In terms of safety, true anaphylaxis does not occur with modern preparations such as iron sucrose and iron gluconate. The novel preparations ferric carboxymaltose and ferumoxytol do not require a test dose and appear to offer a good safety profile, but long-term safety monitoring is mandatory. Conclusions: Intravenous iron offers an effective, feasible route towards reducing the heavy burden of iron-deficiency anaemia in the non-dialysis CKD patient, even in the absence of ESA therapy.