What is parental iron (Intravenous iron) therapy?

From the Guidelines

Parenteral iron supplementation is recommended for patients receiving long-term parenteral nutrition who cannot maintain adequate iron status using enteral iron supplements, with iron sucrose being the most studied and recommended formulation in children 1. When considering parenteral iron therapy, it is essential to weigh the benefits against the potential risks, including adverse drug reactions, which are common with iron dextran but less frequent with newer formulations like iron sucrose and ferric carboxymaltose. Key points to consider when administering parenteral iron include:

• Iron sucrose is the preferred formulation in children due to its safety profile and approval in the USA for use in children from 2 years of age 1.
• Dosing recommendations vary by product, with iron sucrose typically administered at 200-300mg per session, and ferric carboxymaltose at 750-1000mg per dose 1.
• Patients should be assessed for allergies, and vital signs monitored during infusion due to potential hypersensitivity reactions.
• Parenteral iron works by directly replenishing iron stores, allowing for faster correction of anemia than oral supplements, making it valuable for patients with chronic kidney disease, inflammatory bowel disease, or those requiring rapid iron repletion. Some important considerations for parenteral iron administration include:
• Test doses are required for iron dextran but not for ferric gluconate or iron sucrose, unless patients have exhibited sensitivities to iron dextran or other IV iron preparations 1.
• Iron status should be regularly monitored in patients on long-term parenteral nutrition to prevent iron deficiency and overload 1.
• Adverse events associated with parenteral iron preparations include hypotension, nausea, vomiting, diarrhea, pain, fever, dyspnea, pruritus, headaches, and dizziness 1.

From the FDA Drug Label

INDICATIONS & USAGE Intravenous or intramuscular injections of INFeD are indicated for treatment of patients with documented iron deficiency in whom oral administration is unsatisfactory or impossible. PRECAUTIONS General: Unwarranted therapy with parenteral iron will cause excess storage of iron with the consequent possibility of exogenous hemosiderosis.

5 WARNINGS AND PRECAUTIONS 5. 3 Iron Overload Excessive therapy with parenteral iron can lead to excess storage of iron with the possibility of iatrogenic hemosiderosis.

The use of parenteral iron is indicated for the treatment of documented iron deficiency in patients where oral administration is unsatisfactory or impossible 2.

• Key considerations for parenteral iron therapy include the risk of excess iron storage and iatrogenic hemosiderosis if used unwarranted or in excess 2.
• Monitoring of hematologic and iron parameters is necessary for patients receiving parenteral iron to avoid iron overload 3.
• Hypersensitivity reactions and hypotension are potential risks associated with parenteral iron administration, requiring careful administration and monitoring 2 3.

From the Research

Parenteral Iron Therapy

• Parenteral iron therapy is necessary for patients who are intolerant or unresponsive to oral iron therapy, receiving recombinant erythropoietin therapy, or have functional iron deficiency 4
• There are three parenteral iron products available: iron dextran, ferric gluconate, and iron sucrose, each with its own advantages and disadvantages 4

Dosage Regimens

• A study on intravenous iron sucrose found that doses of 200 mg and 300 mg administered over 2 hours appear to be safe, while higher doses (400 mg and 500 mg) had a higher incidence of adverse events 5
• The optimal dosage regimen for parenteral iron preparations may vary depending on the individual patient's needs and response to treatment 5

Iron Supplementation and Erythropoietin Therapy

• Iron supplementation is essential to maximize the effect of erythropoietin-induced erythropoiesis, as stimulation of erythropoiesis can lead to a state of relative iron deficiency 6
• Epoetin, a recombinant human erythropoietin, is used to treat anemia associated with chronic renal failure, and its efficacy is enhanced by iron supplementation 7

Monitoring Glycemic Control

• In patients with diabetic kidney disease undergoing iron or erythropoietin treatment, HbA(1c) values may be unreliable, and complementary markers such as glycated albumin, fructosamine, and 1,5 anhydroglucitol may be useful in assessing glycemic control 8
• These markers can provide a more accurate picture of glycemic control, as HbA(1c) levels may be affected by iron or erythropoietin treatment 8