From the Guidelines
Ferric carboxymaltose is the best intravenous iron formulation due to its high efficacy, convenience, and relatively low risk of adverse effects.
Key Characteristics of Intravenous Iron Formulations
- Ferric carboxymaltose: has a typical single dose of 750-1000 mg, can be administered as a single dose or in two doses one week apart, and has a risk of hypophosphatemia, particularly with repeated dosing 1.
- Ferumoxytol: has a typical single dose of 510-1020 mg, can be administered as a single dose or in two doses, and is also used as a magnetic resonance imaging contrast agent, requiring notification of radiologists if an MRI is planned within 3 months of infusion 1.
- Low-molecular-weight iron dextran (LMWID): has a typical single dose of 1000 mg, can be administered as a single infusion in 1 hour, and carries a black box warning of anaphylaxis in the United States, although this warning is not supported by evidence and is not present in Europe 1.
Administration and Monitoring
- Test dose: required for iron dextran preparations due to the risk of serious anaphylactic reactions, but not necessary for other formulations 1.
- Infusion reactions: can occur with any intravenous iron formulation, and monitoring for these reactions is essential, with treatment available for minor reactions 1.
Clinical Guidelines and Recommendations
- European consensus: recommends intravenous iron as first-line treatment in patients with clinically active inflammatory bowel disease (IBD), previous intolerance to oral iron, hemoglobin below 10 g/dL, and in patients who need erythropoiesis-stimulating agents 1.
- Guidelines for management of iron deficiency anemia: suggest that intravenous iron preparations can replenish iron and hemoglobin concentrations in a single infusion, but serious reactions can occur, and resuscitation facilities should be available 1.
- Simple dosing regimen: a novel and simple scheme has been compared to the Ganzoni-calculated dosing in anemic patients with IBD, showing better efficacy and compliance, as well as a good safety profile, for ferric carboxymaltose 1.
From the FDA Drug Label
12 CLINICAL PHARMACOLOGY 12. 1 Mechanism of Action Venofer is an aqueous complex of poly-nuclear iron (III)-hydroxide in sucrose.
11 DESCRIPTION Venofer (iron sucrose injection, USP), an iron replacement product, is a brown, sterile, aqueous, complex of polynuclear iron (III)-hydroxide in sucrose for intravenous use
The best intravenous iron formulation cannot be determined from the provided information, as the labels only describe the properties and mechanism of action of Venofer (iron sucrose injection, USP) and do not compare it to other formulations 2, 2.
From the Research
Intravenous Iron Formulations
The available intravenous iron formulations include low molecular weight iron dextran, ferumoxytol, iron isomaltoside, ferric carboxymaltose, and ferric derisomaltose 3. These formulations have been developed to prevent uncontrolled release of free iron to the circulation and have been shown to be safe and effective in treating iron deficiency anemia.
Efficacy and Safety
The preponderance of published evidence suggests that there are no major, clinically important differences among the available intravenous iron formulations in terms of either efficacy or safety 3. However, ferric carboxymaltose has been associated with a higher risk of hypophosphatemia compared to ferric derisomaltose 4. The risk of hypersensitivity reactions is low, affecting less than 1% of patients, and can be reduced by choosing a slow infusion rate 4, 5.
Administration and Convenience
A single infusion of a total iron dose is as effective and safe as giving multiple low doses of IV iron, and results in a decreased number of intravenous infusions, a lower cumulative risk for infusion reactions or extravasations, and increased convenience for physicians and patients 3. Ferric derisomaltose has been approved for delivery of 1000 mg iron in a single IV infusion, offering convenience and eliminating adherence concerns 6.
Side Effects and Complications
Intravenous iron preparations are associated with adverse effects, including hypersensitivity reactions and hypophosphatemia 4, 5. The risk of severe hypersensitivity reactions is low, but hypophosphatemia can cause severe and potentially irreversible clinical complications, such as bone pain, osteomalacia, and fractures 4, 5. Treatment-emergent hypophosphatemia is a newly recognized side effect for some formulations, and individual selection of the appropriate iron therapy and evaluation of treatment response are mandatory to safely deliver improved outcomes through intravenous iron therapies 7, 5.
Key Points
- The available intravenous iron formulations are safe and effective in treating iron deficiency anemia 3.
- Ferric carboxymaltose is associated with a higher risk of hypophosphatemia compared to ferric derisomaltose 4.
- A single infusion of a total iron dose is as effective and safe as giving multiple low doses of IV iron 3.
- Intravenous iron preparations are associated with adverse effects, including hypersensitivity reactions and hypophosphatemia 4, 5.