Source: Nutrition  |  Posted 8 years ago

A review of the literature shows no direct evidence of short-term or long-term complications associated with intravenous iron therapy with dextran-free iron compounds, say researchers.

For patients with anaemia associated with end-stage renal disease, treatment with recombinant human erythropoietin (epoetin) is optimised by adequate iron supply that ideally is provided by intravenous (IV) therapy with dextran-free iron compounds. However, there is much concern that excess levels of iron following IV administration may lead to short-term complications (i.e., anaphylactic reactions, response to free iron) and/or long-term complications (i.e., increased infection, cardiovascular disease, oxidative stress). The established benefit of IV iron therapy to optimise epoetin therapy combined with these potential increased risk of complications suggests that IV therapy has become a double-edged sword in the treatment of anaemia in patients with end-stage renal disease.

In this literature review, Ivor Cavill MD, University of Wales College of Medicine, Cardiff, United Kingdom, examined the evidence to date on potential complications associated with IV iron therapy in the setting of epoetin treatment. A review of the data in 2 studies that examined the potential for short-term complications showed that the incidence of serious anaphylactic reactions to IV iron dexatran was 0.7% in 1 study and 0.6% in the other. No direct evidence was found that free iron can exist at levels suggested.

Similarly, data on long-term complications suggest that IV therapy is not solely responsible for increased infection, increased oxidative stress, or cardiovascular disease. Studies on the association between iron and infection do not clarify whether infection is responsible for anaemia or anaemia is responsible for infection, and overall there is a lack of general increase in infection rates in patients with chronic renal failure who receive IV iron and erythropoietic agents. Although increased oxidative stress has been shown []in vitro[], it has not been demonstrated []in vivo[]. Data indicate, however, that unbound reactive iron may occur in the presence of oral ferrous compounds, which can overwhelm the body's ability to manage free radicals and result in death, particularly in children. In terms of cardiovascular disease, conflicting clinical data has been reported with 1 study indicating an association between high serum iron concentrations and an increased risk of myocardial infarction, and another study showing no association between iron intake and increased risk of coronary heart disease or myocardial infarction. Evidence overall does not indicate any direct evidence of increased cardiovascular risk associated with IV iron therapy.

The author concludes that "concerns over excess iron in the body are unfounded and iron is not a two-edged sword. Iron is still required to ensure the optimal use of epoetin therapy."