What are the differences between Injectafer (ferric carboxymaltose), Feraheme (ferumoxytol), and Venofer (iron sucrose) for treating iron deficiency anemia?

Differences Between Injectafer, Feraheme, and Venofer for Iron Deficiency Anemia

The main differences between these intravenous iron preparations are in their dosing capabilities, administration time, and safety profiles, with Injectafer (ferric carboxymaltose) offering the advantage of higher single-dose administration (up to 750-1000mg) compared to Venofer (iron sucrose, 200mg maximum single dose), while Feraheme (ferumoxytol) falls in between with a 510mg single-dose capacity.

Key Characteristics of Each Preparation

Injectafer (Ferric Carboxymaltose)

• Maximum single dose: 750mg (FDA) to 1000mg (EMA) 1
• Administration time: 15 minutes 1
• Total dose capability: Up to 1500mg in two administrations separated by at least 7 days 2
• Unique considerations:
  • Associated with hypophosphatemia 3
  • No test dose required 1
  • Can be delivered as rapid injection or infusion 2

Feraheme (Ferumoxytol)

• Maximum single dose: 510mg 1
• Administration time: 15 minutes 1
• Total dose capability: Up to 1020mg weekly 1
• Unique considerations:
  • Originally developed for chronic kidney disease 1
  • Comparable efficacy to iron sucrose in CKD patients 4
  • Contains 30mg/ml of elemental iron 1

Venofer (Iron Sucrose)

• Maximum single dose: 200mg 1
• Administration time: 10-30 minutes 1
• Total dose capability: Up to 500mg weekly 1
• Unique considerations:
  • Requires multiple visits for full iron repletion 5
  • Well-established safety profile 5
  • Contains 20mg/ml of elemental iron 1

Clinical Efficacy Comparisons

All three preparations effectively treat iron deficiency anemia, but with important differences:

1. Dose efficiency: Injectafer requires fewer administrations (typically two) to deliver a complete treatment course compared to Venofer (which may require 5-10 administrations) 1, 5

2. Speed of hemoglobin response:

   • In comparative studies, ferumoxytol (Feraheme) and iron sucrose (Venofer) showed similar hemoglobin increases (0.8 g/dL vs 0.7 g/dL at 5 weeks) 4
   • Ferric carboxymaltose (Injectafer) typically produces rapid hemoglobin improvement 6, 7

3. Iron store replenishment: All effectively replenish iron stores, but higher single doses of Injectafer may achieve this more rapidly 6

Safety Considerations

1. Hypersensitivity reactions:

   • Iron dextran preparations (not discussed here) have highest risk of serious reactions 1
   • Feraheme, Venofer, and Injectafer have lower risks of serious hypersensitivity reactions 5
   • No test dose is required for Injectafer or Venofer, unlike iron dextran preparations 1

2. Specific adverse effects:

   • Injectafer: Associated with hypophosphatemia, which can be prolonged 3
   • Common side effects across all preparations: headache, dizziness, nausea, and injection site reactions 6
   • Gastrointestinal side effects are less common with IV preparations compared to oral iron 7

Clinical Decision Algorithm

1. For patients needing rapid iron repletion (Hb < 10 g/dL or clinically active disease):

   • Choose Injectafer if total dose needed is high and minimal visits are desired 1
   • Choose Feraheme if moderate dose is needed with fewer visits than Venofer 1
   • Choose Venofer if smaller, more gradual dosing is preferred or if there are concerns about hypophosphatemia 1, 3

2. For patients with chronic kidney disease:

   • All three options are suitable, with similar efficacy between Feraheme and Venofer specifically demonstrated in this population 4
   • Consider Injectafer for non-dialysis CKD patients when fewer visits are desired 3

3. For patients with inflammatory bowel disease:

   • Injectafer has been extensively studied in this population 1, 7
   • Higher single-dose capability may be advantageous 1

Practical Considerations

• Cost: Varies by region and insurance coverage, but Venofer is generally less expensive per gram of iron than Injectafer 1
• Administration setting: All require healthcare facility administration with resuscitation equipment available 1
• Number of visits: Injectafer requires the fewest visits (typically 2), Feraheme intermediate (2-3), and Venofer the most (5-10 depending on total dose needed) 1, 5

When selecting between these IV iron preparations, the key factors to consider are the total iron dose needed, desired administration time, number of possible visits, and patient-specific risk factors such as kidney disease or history of hypophosphatemia.