Article date: August 2013
Intravenous (IV) iron products are indicated in the treatment of iron deficiency and anaemia when iron supplements cannot be given or have not worked. Hypersensitivity reactions are well known to occur rarely with IV iron products, and may be life-threatening or fatal. Warnings about this risk are given in the product information.
A European review of IV iron products has taken place after concerns in France about the risk of serious hypersensitivity reactions, especially in pregnant women. The review has recommended strengthened advice to ensure correct prescribing and administration, and early detection and effective management of hypersensitivity reactions.
Further information on hypersensitivity reactions
Serious hypersensitivity reactions, including life-threatening and fatal anaphylactic and anaphylactoid reactions, have been reported in patients receiving IV iron. These reactions can occur even when a previous administration has been tolerated (including a negative test dose). Caution is therefore needed with every dose of IV iron, even if previous administrations have been well tolerated.
The product should be given in accordance with the specific posology and method of administration stated in the product information. IV iron should only be given in an environment where the patient can be adequately monitored, and where resuscitation facilities are available. In case of a hypersensitivity reaction, treatment should be stopped immediately and appropriate management initiated.
Use in pregnancy
Iron-deficiency anaemia in the first trimester of pregnancy can usually be treated with oral iron (ie, IV iron should not be used). Later in pregnancy, any benefits of using IV iron should be carefully weighed against the risks: anaphylactic or anaphylactoid reactions could have serious consequences for both mother and foetus.
Previously, an initial test dose has been recommended for some IV iron products before administration of the first dose to a new patient. However, there are no clear data that an initial test dose minimises risk: conversely, it may give false reassurance because hypersensitivity reactions have been reported in patients that had a negative initial test dose. Therefore, an initial test dose on first use of an IV iron product for a patient is no longer recommended. All references to this recommendation will be removed from relevant product information.
Please note that the advice for administration of a product remains otherwise unchanged. For example, for iron dextrans (CosmoFer), a slower rate of administration for the first 25 mg of iron is required for every dose.
Advice for healthcare professionals
The prescribing, dosing, administration, and safety information differs between IV iron product formulations, and the individual product information should be consulted before and during use.
An IV iron product should not be used in patients with known hypersensitivity to the active substance, the product itself, or any of its excipients; it should also not be used in patients with known serious hypersensitivity to any other parenteral iron product.
The risk of hypersensitivity is increased in patients with: known allergies (including drug allergies); immune or inflammatory conditions (eg, systemic lupus erythematosus, rheumatoid arthritis); or those with a history of severe asthma, eczema, or other atopic allergy. In these patients, IV iron products should only be used if the benefits are clearly judged to outweigh the potential risks.
IV iron should not be used during pregnancy unless clearly necessary. Treatment should be confined to the 2nd or 3rd trimesters, if the benefit is clearly judged to outweigh the potential risks for both mother and foetus.
Administration and monitoring
IV iron should be administered in strict accordance with the posology and method of administration described in the product information for each individual product (note that advice varies between products).
Caution is needed with every dose of intravenous iron that is given, even if previous administrations have been well tolerated.
IV iron products should only be administered when staff trained to evaluate and manage anaphylactic or anaphylactoid reactions—as well as resuscitation facilities—are immediately available.
Patients should be closely monitored for signs of hypersensitivity during and for at least 30 minutes after every administration of an IV iron product.
In the event of a hypersensitivity reaction, treatment should be stopped immediately and appropriate management initiated.
Information for patients
Healthcare professionals should inform patients of the risk and potential seriousness of a hypersensitivity reaction before every administration. Patients should be informed of the relevant symptoms and advised to tell their doctor or nurse straight away if any of these occur
Report suspected adverse drug reactions
The safety of IV iron products will continue to be monitored closely in the UK and Europe. You can help by reporting via the Yellow Card Scheme any suspected adverse reactions to IV iron products. We are particularly interested in reports of suspected anaphylactic or anaphylactoid hypersensitivity reactions. Please ensure to include the name of the specific product administered (www.mhra.gov.uk/yellowcard).
Article citation: Drug Safety Update vol 7, issue 1 August 2013: A1.