What are the guidelines for Intravenous (IV) Iron (Fe) supplementation due to iron deficiency?

From the Guidelines

Intravenous iron therapy is recommended for patients with iron deficiency who have failed oral iron therapy, cannot tolerate oral iron, have severe anemia, or require rapid iron repletion. The most commonly used IV iron formulations include iron sucrose (Venofer), ferric gluconate (Ferrlecit), ferumoxytol (Feraheme), ferric carboxymaltose (Injectafer), and iron dextran (INFeD) 1.

Key Considerations

• Dosing varies by preparation: iron sucrose is typically given as 200-300mg per session, ferric gluconate as 125-250mg, ferumoxytol as 510mg, ferric carboxymaltose as 750-1000mg, and iron dextran as 1000mg 1.
• Most regimens require multiple doses to achieve full iron repletion, with total doses calculated based on the patient's weight and hemoglobin level using the Ganzoni formula or simplified dosing tables 1.
• Prior to administration, patients should have confirmed iron deficiency with ferritin <30 ng/mL or ferritin <100 ng/mL with transferrin saturation <20% 1.
• During administration, patients should be monitored for hypersensitivity reactions, particularly in the first 30 minutes 1.

Benefits and Risks

• IV iron therapy works by bypassing the gastrointestinal absorption limitations of oral iron, allowing for direct delivery to transferrin in the bloodstream and more rapid correction of iron stores, which is particularly beneficial in conditions with chronic inflammation where hepcidin levels may block oral iron absorption 1.
• Life-threatening infusion reactions are extremely rare, and concern for their occurrence should not be a barrier to the use of IV iron 1.
• The choice of IV iron formulation should be based on its registration for the specific age group or a proven good safety profile in adults during several years of postmarketing surveillance 1.

Administration and Monitoring

• The total intravenous iron cumulative doses should be calculated on the basis of formulas of the deficit of body iron, allowing for the correction of the Hb deficit and rebuilding the iron stores 1.
• Serum ferritin levels should be monitored and preferably should not exceed 500 mg/L to avoid toxicity of iron overload, especially in children and adolescents 1.
• IV iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those that require more than 2 infusions 1.

From the FDA Drug Label

Intravenous or intramuscular injections of INFeD are indicated for treatment of patients with documented iron deficiency in whom oral administration is unsatisfactory or impossible. The guidelines for IV iron due to low iron are to use it when oral administration is unsatisfactory or impossible in patients with documented iron deficiency.

• Key points:
  • Indication: treatment of iron deficiency
  • Administration: intravenous or intramuscular
  • Patient selection: those with documented iron deficiency where oral administration is unsatisfactory or impossible 2

From the Research

Guidelines for IV Iron Due to Low Iron

• The use of intravenous iron has increased significantly in the last decade, but concerns remain about indications and administration 3.
• Intravenous iron preparations are indicated for the treatment of iron deficiency when oral preparations are ineffective or cannot be used, and have applicability in a wide range of clinical contexts, including chronic inflammatory conditions, perioperative settings, and disorders associated with chronic blood loss 3, 4.
• There are three different generations of parenteral iron preparations, which differ in terms of stability, safety, and dosage 4.
• The third generation of parenteral iron preparations, including ferric carboxymaltose, iron isomaltoside, and ferumoxytol, are characterized by high complex stability and comparable safety, allowing for rapid application of high doses of iron 4, 5.
• High molecular weight iron dextran, as a representative of the first generation of iron preparations, should no longer be used if possible, due to the risk of serious anaphylactic reactions 4.
• Second-generation intravenous iron formulations, including iron sucrose and ferric gluconate, are effective in the management of iron deficiency anemia, but require frequent visits to the clinic or doctor due to the need for low doses 6.
• Newer intravenous iron preparations, such as ferric carboxymaltose, offer effective and rapid correction of iron deficiency anemia, and can be safely administered in a single dose of 1000 mg of iron, reducing the need for frequent clinic visits 6, 7.
• The administration of intravenous iron should be guided by the patient's individual needs and medical history, and should be monitored for potential side effects and adverse reactions 3, 7.