Administration of Intravenous Iron in Patients with Active Soft Tissue Infection

Introduction to Risks and Considerations

• The administration of intravenous iron is associated with an increased risk of infection (RR 1.16; 95% CI 1.03-1.29) in a meta-analysis of 154 randomized clinical trials including 32,762 participants, with moderate-quality evidence according to the GRADE framework 1, 2, 3.
• This translates to 16 additional people per 1,000 developing an infection when administered intravenous iron (95% CI: 3-29 additional people) 4.

Mechanism and Pathophysiology

• Intravenous iron increases levels of circulating non-transferrin-bound iron, which promotes the growth of pathogens requiring iron for replication 5, 6, 7.
• It interferes with "nutritional immunity," the body's natural process of retaining free iron during infections to limit bacterial growth 5, 6, 7.

Specific Considerations in Active Infection

• Common commensal bacteria frequently implicated in nosocomial infections, such as Staphylococcus aureus and Staphylococcus epidermidis, have developed iron acquisition mechanisms and can become pathogenic under appropriate conditions 8, 9.
• Exogenous iron can convert benign bacterial colonization into virulent infection 8, 9.

Practical Recommendations

• The administration of intravenous iron should be deferred until the soft tissue infection is completely resolved and treated 8, 9.
• If anemia is symptomatic and requires urgent treatment during active infection, consider red blood cell transfusion if anemia is severe and symptomatic 7.

Balancing Benefits and Risks

• The benefits of treating anemia must be balanced against the risk of developing or exacerbating infection 8, 6, 9.
• This balance is particularly critical in clinical settings with a high endemic burden of infections, where iron supplementation may not be effective or safe 8, 9.