Safety of intravenous iron formulations: facts and folklore.

Abstract

It is unlikely that anyone reading this review was not taught that intravenous (IV) iron is dangerous. While early preparations were associated with an unacceptably high rate of serious adverse events, most notably anaphylactic shock, newer formulations with carbohydrate shells which bind the elemental iron more tightly, allowing for a much slower release, are very much safer with serious toxicity being marginal to absent in prospective trials. The perception of risk is fueled by misinterpretation and misinformation of the clinical nature of minor infusion reactions1, inappropriate use of premedication with diphenhydramine2 and inferences made about the relative safety of the available formulations using spontaneous adverse event reporting systems, methodologies proscribed by regulatory agencies3,4. In this article we review published evidence on the relative safety of the different formulations, highlight errors in interpretation and intervention when minor infusion reactions occur, and posit a paradigm for maximising safety with this underutilised therapeutic tool.