Hypersensitivity reactions and deaths associated with intravenous iron preparations

Parenteral iron therapy is an accepted adjunctive management of anaemia in kidney disease. Newer agents may have fewer severe hypersensitivity adverse events (AE) compared with iron dextrans (ID). The rate of type 1 AE to iron sucrose (IS) and sodium ferric gluconate (SFG) relative to ID is unclear. We used the US Food and Drug Administration's Freedom of Information (FOI) surveillance database to compare the type 1 AE profiles for the three intravenous iron preparations available in the United States.

We tabulated reports received by the FOI database between January 1997 and September 2002, and calculated 100 mg dose equivalents for the treated population for each agent. We developed four clinical categories describing hypersensitivity AE (anaphylaxis, anaphylactoid reaction, urticaria and angioedema) and an algorithm describing anaphylaxis, for specific analyses.

All-event reporting rates were 29.2, 10.5 and 4.2 reports/million 100 mg dose equivalents, while all-fatal-event reporting rates were 1.4, 0.6 and 0.0 reports/million 100 mg dose equivalents for ID, SFG and IS, respectively. ID had the highest reporting rates in all four clinical categories and the anaphylaxis algorithm. SFG had intermediate reporting rates for urticaria, anaphylactoid reaction and the anaphylaxis algorithm, and a zero reporting rate for the anaphylaxis clinical category. IS had either the lowest or a zero reporting rate in all clinical categories/algorithm.

These findings confirm a higher risk for AE, especially serious type 1 reactions, with ID therapy than with newer intravenous iron products and also suggest that IS carries the lowest risk for hypersensitivity reactions.