What is the dosage of intravenous (IV) iron for treating iron deficiency anemia?

From the Guidelines

The recommended dosage of intravenous (IV) iron for treating iron deficiency anemia is 1000 mg of iron given as a single dose or divided into multiple infusions, with specific products having different dosing protocols, such as ferric carboxymaltose (Injectafer) as 750 mg followed by another 750 mg in 7 days 1. To determine the appropriate dose of IV iron, the Ganzoni formula can be used: Total iron deficit (mg) = [Target Hb - Actual Hb (g/dL)] × 2.4 × weight (kg) + 500 mg (for iron stores) 1. Key considerations for IV iron administration include:

• Confirming iron deficiency with laboratory tests (ferritin <30 ng/mL or transferrin saturation <20%) 1
• Ruling out other causes of anemia 1
• Ensuring the patient has either failed oral iron therapy or has a condition where oral iron is inappropriate 1
• Monitoring for infusion reactions during administration 1
• Checking hemoglobin levels 2-4 weeks after treatment to assess response 1 It is also important to note that IV iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those that require more than 2 infusions 1. Specific products have different dosing protocols, such as:
• Iron sucrose (Venofer) typically given as 200 mg per session up to 5 sessions
• Ferric carboxymaltose (Injectafer) as 750 mg followed by another 750 mg in 7 days
• Iron dextran (INFeD) as a single 1000 mg dose after a test dose 1.

From the FDA Drug Label

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. In 22 patients undergoing hemodialysis and receiving erythropoietin (recombinant human erythropoietin) therapy treated with iron sucrose containing 100 mg of iron, three times weekly for three weeks, significant increases in serum iron and serum ferritin and significant decreases in total iron binding capacity occurred four weeks from the initiation of iron sucrose treatment. A study evaluating Venofer containing 100 mg of iron labeled with 52Fe/59Fe in patients with iron deficiency showed that a significant amount of the administered iron is distributed to the liver, spleen and bone marrow and that the bone marrow is an irreversible iron trapping compartment In a single-dose PK study of Venofer, patients with NDD-CKD ages 12 to 16 (N=11) received intravenous bolus doses of Venofer at 7 mg/kg (maximum 200 mg) administered over 5 minutes.

The dosage of intravenous (IV) iron for treating iron deficiency anemia is:

• 100 mg of iron, three times weekly for three weeks, as seen in the study with iron sucrose 2
• 7 mg/kg (maximum 200 mg) administered over 5 minutes, as seen in the single-dose PK study of Venofer in patients with NDD-CKD ages 12 to 16 2
• 1.5 mg/kg or 3.0 mg/kg of elemental iron (up to a maximum dose of 125 mg of elemental iron) in 25 mL 0.9% sodium chloride, infused intravenously over 1 hour during each hemodialysis session for eight sequential dialysis sessions, as seen in Study C with ferric gluconate 3

From the Research

Dosage of Intravenous (IV) Iron for Treating Iron Deficiency Anemia

• The dosage of IV iron for treating iron deficiency anemia can vary depending on the patient's iron deficit and the specific IV iron preparation used 4.
• Studies have shown that a total cumulative dose of 1000 mg of IV iron may be insufficient for iron repletion in a majority of patients with iron deficiency anemia, and a dose of 1500 mg is closer to the actual iron deficit in these patients 4.
• IV iron preparations can facilitate rapid iron repletion in one or two doses, with some preparations allowing for administration of full therapeutic doses in 15 to 60 minutes 5, 6.
• The choice of IV iron preparation and dosage should be based on individual patient needs and factors such as the presence of inflammation, the time available for iron replenishment, and the anticipated risk of side-effects or intolerance 7.

Administration and Safety Considerations

• IV iron preparations are generally well-tolerated, but adverse events can occur, including complement-mediated minor infusion reactions and treatment-emergent hypophosphatemia 6.
• The risk of adverse events can be anticipated and managed with proper administration and monitoring 7, 6.
• The use of IV iron has become a major component of the therapeutic armamentarium for iron deficiency and iron deficiency anemia, and its safety profile has improved with the development of newer formulations 5, 6.