From the Guidelines
Iron dextran is the form of intravenous iron most commonly associated with life-threatening anaphylactic reactions. This is due to the formation of antibodies against the dextran component, which can trigger massive histamine release and potentially fatal systemic reactions 1. The estimated incidence of anaphylaxis with iron dextran is approximately 0.6-0.7%, which is significantly higher than the incidence with newer formulations such as iron sucrose, ferric gluconate, and ferric carboxymaltose 1.
Some key points to consider when administering intravenous iron preparations include:
- Iron dextran carries a higher risk of anaphylactic reactions compared to other intravenous iron preparations 1
- Test doses should be considered for dextran-containing products to minimize the risk of anaphylaxis 1
- Newer formulations such as iron sucrose, ferric gluconate, and ferric carboxymaltose have a lower risk of anaphylactic reactions compared to iron dextran 1
- Clinicians should be prepared to manage hypersensitivity reactions and have resuscitation equipment available when administering any intravenous iron product 1
In terms of the specific options provided, b. Iron Dextran is the correct answer, as it is the form of intravenous iron most commonly associated with life-threatening anaphylactic reactions. The other options, a. Ferrous Sulfate, c. Sodium Ferric Gluconate, and d. Iron Sucrose, are not as commonly associated with anaphylactic reactions as iron dextran 1.
From the FDA Drug Label
Immune System: anaphylactic-type reactions The correct answer is b. Iron Dextran, however the provided drug label is for Sodium Ferric Gluconate. The FDA drug label does not answer the question.
From the Research
Forms of Intravenous Iron and Anaphylactic Reactions
- The form of intravenous (IV) iron most commonly associated with life-threatening anaphylactic reactions is Iron Dextran 2, 3, 4.
- Studies have shown that Iron Dextran has a higher risk of anaphylaxis compared to other IV iron products, such as Iron Sucrose and Sodium Ferric Gluconate 3, 4.
- The risk of anaphylaxis with Iron Dextran is estimated to be around 68 per 100,000 persons, which is significantly higher than the risk associated with other IV iron products 3.
- In contrast, Iron Sucrose and Sodium Ferric Gluconate have been shown to have a lower risk of anaphylaxis, with estimated risks of around 24 per 100,000 persons and 1.5 cases per 10,000 first administrations, respectively 3, 4.
- Ferumoxytol has also been associated with a higher risk of anaphylaxis compared to Iron Sucrose, but the risk is still lower than that associated with Iron Dextran 4.
Comparison of IV Iron Products
- A study comparing the risk of anaphylaxis among IV iron products found that Iron Dextran had an adjusted odds ratio (OR) of 2.6 for anaphylaxis compared to non-dextran IV iron products 3.
- Another study found that the adjusted incidence rates for anaphylaxis per 10,000 first administrations were 9.8 cases for Iron Dextran, 4.0 cases for Ferumoxytol, 1.5 cases for Ferric Gluconate, 1.2 cases for Iron Sucrose, and 0.8 cases for Ferric Carboxymaltose 4.
- The introduction of second-generation IV iron formulations, such as Iron Sucrose and Ferric Gluconate, has improved the safety profile of IV iron therapy, with a lower risk of anaphylaxis compared to Iron Dextran 5.