What is the use of intravenous (IV) iron?

From the Guidelines

Intravenous (IV) iron therapy is recommended for patients with iron deficiency anemia who cannot tolerate oral iron supplements, have malabsorption issues, or require rapid iron repletion, with ferric carboxymaltose (Injectafer) being a preferred formulation due to its efficacy and safety profile, as demonstrated in recent studies 1. When considering IV iron therapy, several formulations are available, including iron sucrose (Venofer), ferric carboxymaltose (Injectafer), ferumoxytol (Feraheme), and iron dextran (INFeD) 1.

• Dosing varies by product:
  • iron sucrose typically 200-300mg per session over multiple visits
  • ferric carboxymaltose 750mg in two doses separated by at least 7 days
  • ferumoxytol 510mg in two doses 3-8 days apart
  • iron dextran as a single total dose infusion Administration should occur in a monitored setting due to the potential for hypersensitivity reactions, with test doses recommended for iron dextran 1.
• Common side effects include:
  • hypotension
  • nausea
  • injection site reactions IV iron bypasses the gastrointestinal tract, allowing for direct iron delivery to transferrin and the reticuloendothelial system, which makes it particularly effective for patients with inflammatory conditions where hepcidin blocks oral iron absorption 1.
• Laboratory monitoring should include:
  • hemoglobin
  • ferritin
  • transferrin saturation before treatment and 4-8 weeks after completion, with follow-up assessments as needed to ensure optimal iron levels and minimize the risk of treatment-emergent hypophosphatemia 1. Recent expert consensus guidelines emphasize the importance of proper administration, monitoring, and management of infusion reactions to ensure safe and effective use of IV iron therapy 1.

From the FDA Drug Label

12 CLINICAL PHARMACOLOGY

1. 1 Mechanism of Action Venofer is an aqueous complex of poly-nuclear iron (III)-hydroxide in sucrose. Following intravenous administration, Venofer is dissociated into iron and sucrose and the iron is transported as a complex with transferrin to target cells including erythroid precursor cells. The iron in the precursor cells is incorporated into hemoglobin as the cells mature into red blood cells.

The mechanism of action of IV iron, specifically iron sucrose, involves the dissociation of iron and sucrose after intravenous administration. The iron is then transported to target cells, including erythroid precursor cells, where it is incorporated into hemoglobin.

• Key points:
  • IV iron is dissociated into iron and sucrose after administration
  • Iron is transported to target cells with transferrin
  • Iron is incorporated into hemoglobin in erythroid precursor cells 2

From the Research

IV Iron Administration

• IV iron is used in patients who cannot tolerate or absorb oral preparations 3
• Modern parenteral iron formulations have substantially altered iron treatment and enable rapid, safe total-dose iron replacement 4
• Intravenous iron replacement can be done in patients in whom oral iron is not effective or contraindicated 5
• IV iron preparations are indicated for the treatment of iron deficiency when oral preparations are ineffective or cannot be used 6

Indications for IV Iron

• Chronic inflammatory conditions 4, 6
• Perioperative settings 6
• Disorders associated with chronic blood loss 6
• Pregnancy 6
• Heavy menstrual bleeding 6
• Surgery 6

Considerations for IV Iron Administration

• The presence of inflammation 6
• The time available for iron replenishment 6
• The anticipated risk of side-effects or intolerance 6
• Adverse events occurring with intravenous iron can be anticipated according to when they typically occur 6