Comparison of rates of reported adverse events associated with i.v. iron products in the United States

Purpose. An analysis of reported adverse events (AEs) among patients using i.v. iron products, including the newer agent ferumoxytol, is presented. Methods. All AE reports to the Food and Drug Administration (FDA) citing iron sucrose, ferric gluconate, high- and low-molecular-weight iron dextran products, or ferumoxytol from October 2009 through June 2010 were evaluated. The rates of various classifications of reported AEs were calculated on a per-unit-sold basis and, for comparison of products supplied in different unit sizes, also in terms of 100-mg dose equivalents (DEq) of iron. Results. A total of 197 reported AEs were identified (a cumulative rate of 14.1 AEs per million units sold). The rates of all AE classifications combined ranged from 5.25 to 746 per million units sold for iron sucrose and ferumoxytol, respectively; using the other method of calculation, the rates ranged from 5.24 per million DEq (iron sucrose) to 147 per million DEq (ferumoxytol). Relative to iron sucrose and sodium ferric gluconate, ferumoxytol was associated with significantly elevated risks of death (odds ratio [OR], 475 and 156, respectively; p < 0.0001), serious nonfatal AEs (OR, 263 and 121, respectively; p < 0.0001), and all evaluated AE classifications combined (OR, 142 and 109, respectively; p < 0.05). Conclusion. Analysis of reports submitted to FDA revealed large differences among i.v. iron products in reported deaths, serious AEs, other major AEs, and other AEs. Iron sucrose and sodium ferric gluconate were associated with much lower rates of AEs per million units sold than iron dextran or ferumoxytol, which were associated with the highest rates of all reported AE classifications.