What is the indication for intravenous (IV) iron therapy?

From the Guidelines

Intravenous (IV) iron is indicated for patients with iron deficiency anemia who cannot tolerate oral iron or have not responded to oral iron supplementation, as evidenced by a lack of increase in hemoglobin levels or ferritin stores 1.

Key Considerations for IV Iron Administration

• IV iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those that require more than 2 infusions, as stated in the AGA clinical practice update on management of iron deficiency anemia 1.
• Common IV iron formulations include iron sucrose, ferric carboxymaltose, iron dextran, ferumoxytol, and ferric derisomaltose, with varying dosing regimens and administration protocols 1.
• Treatment is indicated for patients with iron deficiency anemia who have failed oral therapy, have inflammatory bowel disease, chronic kidney disease, heart failure, or during pregnancy when rapid correction is needed 1.

Administration and Monitoring

• IV iron should be administered in a monitored healthcare setting, with protocols varying by specific product and institutional guidelines 1.
• Side effects may include infusion reactions, hypophosphatemia (particularly with ferric carboxymaltose), and rarely anaphylaxis, with management strategies including slowing the infusion rate or using corticosteroids for more severe reactions 1.

Patient Selection and Response

• Patients should be selected for IV iron therapy based on their inability to tolerate oral iron or lack of response to oral iron supplementation, with expected increases in hemoglobin levels and ferritin stores within 2 weeks and 1 month, respectively 1.
• Adherent patients on oral iron should have a reasonable expectation of improved ferritin levels within a month, and if these parameters are not met, IV iron should be considered 1.

From the FDA Drug Label

2 DOSAGE AND ADMINISTRATION

2.1 Recommended Dosage Recommended Dosage for Treatment of Iron Deficiency Anemia For patients weighing 50 kg or more, the recommended dosage is: Injectafer 750 mg intravenously in two doses separated by at least 7 days for a total cumulative dose of 1,500 mg of iron per course In adult patients, Injectafer 15 mg/kg body weight up to a maximum of 1,000 mg intravenously may be administered as a single-dose per course.

The recommended dosage of IV iron (ferric carboxymaltose) is 750 mg intravenously in two doses separated by at least 7 days for a total cumulative dose of 1,500 mg of iron per course for patients weighing 50 kg or more, or 15 mg/kg body weight up to a maximum of 1,000 mg intravenously as a single-dose per course in adult patients 2.

From the Research

IV Iron Therapy

• IV iron therapy is a safe and effective treatment for iron deficiency anemia, especially in patients who cannot tolerate oral iron supplements or require rapid replenishment of iron stores 3, 4, 5, 6.
• Modern IV iron preparations, such as ferric carboxymaltose, can correct iron deficiency with fewer doses and are better tolerated than older formulations 3, 5, 6.

Desensitization Protocols

• Desensitization protocols have been developed to allow patients with a history of hypersensitivity reactions to IV iron to receive treatment safely 3, 7.
• A novel 11-step desensitization protocol for ferric carboxymaltose has been shown to be well-tolerated and effective in patients with a history of anaphylaxis to IV iron 3.
• A one-bag 8-step desensitization protocol for ferric carboxymaltose has also been developed and successfully applied in patients with a history of hypersensitivity reactions to iron preparations 7.

Indications and Administration

• IV iron therapy is indicated for the treatment of iron deficiency anemia when oral preparations are ineffective or cannot be used 4, 5, 6.
• IV iron preparations can be administered in different doses and formulations, allowing for flexible treatment options 4, 5, 6.
• The choice of IV iron preparation and dosing regimen should be individualized based on the patient's clinical needs and risk factors for adverse reactions 4, 5.

Safety and Efficacy

• Modern IV iron preparations have a low risk of severe infusion reactions, affecting less than 1% of patients 5.
• However, IV iron therapy can be associated with hypophosphatemia and other biochemical changes, which can cause severe and potentially irreversible clinical complications 5.
• The efficacy and safety of IV iron therapy have been demonstrated in various clinical trials and studies, making it a valuable treatment option for iron deficiency anemia 3, 4, 5, 6.