Evolution of iv iron compounds over the last century.

Administration of intravenous (IV) iron has become pivotal in the management of anaemia in patients with chronic kidney disease (CKD). Since parenteral iron was first introduced for human use in the 1930s, things have come a long way. Seventy years ago, iron was toxic, administered as an iron oxyhydroxide complex. This problem was circumvented with the introduction of compounds containing iron in a core surrounded by a carbohydrate shell. The carbohydrate shell consists of molecules such as dextran, sucrose, dextrin or gluconate. The first dextran-containing IV iron preparations carried a small risk of anaphylaxis, but the more recently introduced low molecular weight iron dextran preparation has significantly less risk of this. Iron reactions occur with all IV iron preparations, but are generally not thought to be immune based. Recently, newer IV iron preparations have appeared in the market, including Ferumoxytol (Feraheme) and ferric carboxymaltose (Ferinject). These latest IV iron preparations do not contain a requirement for a test dose, and a much higher dose of iron can be delivered as a single administration. Thus, giving supplemental iron to man has come a long way since 1930s; we are now in an era when we are able to administer higher doses of iron with acceptable safety and without significant adverse effects. However, the long-term safety of the newer IV iron preparations is not yet established.