From the Guidelines
For individuals allergic to oral iron supplements and Venofer (iron sucrose), alternative iron formulations like Ferrlecit (sodium ferric gluconate) or Feraheme (ferumoxytol) may be considered, as they have distinct molecular structures that might not trigger the same allergic response. These options are supported by recent guidelines that emphasize the safety and efficacy of various IV iron preparations 1.
Key Considerations
- Low molecular weight iron dextran (INFeD) is another option, though it carries a small risk of anaphylaxis and typically requires a test dose, as highlighted in a study from 2017 1.
- In severe cases where all IV iron preparations are contraindicated, red blood cell transfusions might be necessary for acute management of severe anemia.
- Iron management should always be supervised by a healthcare provider who can monitor for reactions and adjust treatment accordingly.
- The provider may also consider premedication with antihistamines or corticosteroids before attempting alternative IV iron formulations to reduce the risk of allergic reactions, a strategy that aligns with recommendations for managing infusion reactions 1.
- The underlying cause of iron deficiency should also be addressed simultaneously to prevent recurrence.
Administration and Monitoring
- It is recommended that the test dose and subsequent doses of any IV iron formulation be administered by personnel trained to provide emergency treatment and that there be immediate access to the medications needed for the treatment in the rare case of a serious allergic reaction, as advised in guidelines from 2001 1.
- The choice of IV iron formulation should be based on the individual patient's needs and medical history, considering factors such as the severity of iron deficiency, the presence of comorbid conditions, and the risk of adverse reactions.
- Recent expert consensus guidelines provide a comprehensive framework for the administration of IV iron, recognition and management of infusion reactions, and treatment-emergent hypophosphatemia, offering valuable guidance for healthcare providers 1.
From the FDA Drug Label
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. Administer Injectafer intravenously, either as an undiluted slow intravenous push or by infusion.
The alternative method for administering iron to a patient with an allergy to oral iron and Venofer (iron sucrose) is intravenous administration of Injectafer (ferric carboxymaltose). The dosage and administration of Injectafer vary based on the patient's weight and medical condition, and it is essential to follow the recommended dosage and administration guidelines to minimize the risk of adverse reactions 2.
- Key considerations:
- Patients weighing 50 kg or more: 750 mg intravenously in two doses separated by at least 7 days
- Adult patients: 15 mg/kg body weight up to a maximum of 1,000 mg intravenously as a single-dose per course
- Administration: intravenous push or infusion, with monitoring for signs and symptoms of hypersensitivity reactions and hypertension.
From the Research
Alternative Methods for Administering Iron
Given the patient's allergy to oral iron and Venofer (iron sucrose), alternative methods for administering iron can be considered. These include:
- Intravenous iron formulations other than iron sucrose, such as iron dextran, iron derisomaltose, ferric carboxymaltose, ferrumoxytol, and sodium ferric gluconate 3
- These formulations can be infused at different doses and allow correction of total iron deficit with single or repeated doses in 1-2 weeks depending on the specific formulation 3
Precautions and Management
When administering intravenous iron, precautions should be taken to minimize the risk of hypersensitivity reactions, including:
- Meticulous observation and monitoring of the patient during infusion 4, 5, 6, 7
- Starting the infusion at a low rate for a few minutes to assess for any adverse reactions 6
- Having a plan in place for prompt recognition and severity-related interventions by well-trained medical and nursing staff in the event of an adverse reaction 4, 5, 6, 7
- Identifying patients with increased risk of hypersensitivity or contraindications for intravenous iron, such as a previous reaction to an iron infusion, multiple drug allergies, atopic diseases, and high serum tryptase levels 4, 5, 6, 7
Considerations for Specific Formulations
Different intravenous iron formulations have varying risks and benefits, including: