Iron
Work in Progress Updated Feb 4, 2026
Core Concepts
IV iron is used for the treatment of iron deficiency anemia when oral iron is effective or not tolerated.
Formulations available in the United States include low-molecular-weight iron dextran (LWMID), ferric gluconate, iron sucrose, ferumoxytol, iron isomaltoside, and ferric carboxymaltose.
High-molecular weight iron dextrans
Anaphylactic reactions—when high-molecular weight dextrans are excluded—occur with an incidence of < 1 in 200,000.
Significant differences in reaction risk have not been shown among low-molecular weight iron dextran, iron sucrose, ferric gluconate, and ferric carboxymaltose.
Most IV iron immediate hypersensitivity reactions are mediated through complement-activation related pseudoallergy (CARPA). Rarely, hypersensitivity reactions are IgE-mediated.
Symptoms of minor infusion reactions to IV iron include—flushing, chest/back tightness, myalgias—and, importantly, do not have any features of anaphylaxis.
Labile, or also called “free,” iron is associated with minor infusion reactions to IV iron.
As most hypersensitivity reactions are non-IgE-mediated—rather via CARPA—skin testing has limited utility for evaluating IV iron hypersensitivity reactions; however, it may help detect the rare patients with IgE-mediated hypersensitivity.
Approaches for patients with history of mild to moderate IV iron reactions include: switching to an alternative IV iron formulation, slowing the infusion rate (e.g., 10% of recommended rate during the first 10 to 15 minutes), and/or pre-treatment with non-sedating, second generation antihistamines.
For patients with a history of anaphylactic reactions to IV iron, desensitization can be considered, such as ferric gluconate.
| Brand Name | Generic Name | Molecular Weight (kDa) | Labile Iron (% of dose) |
|---|---|---|---|
| Ferrlecit | Iron gluconate | 289-440 | 3.3 |
| Venofer | Iron sucrose | 30-60 | 3.5 |
| Monofer | Iron isomaltoside | 150 | 1 |
| Injectafer | Ferric carboxymaltose | 150 | 0.6 |
| InFeD | LMWID | 165 | 2 |
| FeraHeme | Ferumoxytol | 750 | 0.8 |
References
Gómez-Ramírez S, Shander A, Spahn DR, et al. Prevention and management of acute reactions to intravenous iron in surgical patients. Blood Transfusion. Published online April 10, 2019. doi:10.2450/2018.0156-18
Muñoz M, Gómez-Ramírez S, Bhandari S. The safety of available treatment options for iron-deficiency anemia. Expert Opin Drug Saf 2018; 17: 149-59.