Some of the reactions such as chest pain, flushing can occur quickly within minutes (i.e., Fishbane reaction) with some forms of iron preparations.
Many of these reactions are self-limiting, resolve within 15 minutes, and can be easily managed with either stopping the IV, re-trying again, and re-administering at a slower rate. In the past it was advised to give precautionary treatments such as Benadryl or possibly Epinephrine and it turns out such measures appears to have made matters worse. Stepping back and allowing the reaction to pass has been shown to be the best treatment option for most cases. Low levels of phosphorus can be linked to such complement-immune reactions.
A review and meta-analysis from 2021 also suggest that intravenous iron may increase a person’s risk of infection, and this may need to be considered when looking at the risk vs benefit when using this route of administration.
However, it is also important to keep in mind that being low in iron, or anemic may also increase infection risk as well. It is not advised to receive iron if you are dealing with a known active infection.
Some patients with a history of asthma, eczema, or reactive immune disease such a rheumatoid arthritis, for more precautionary purposes, may require premedication before starting (i.e., corticosteroid) and which may also be advisable to continue for several days following intravenous iron. This would be assessed on a case-by-case basis.
Again, to emphasize that new research suggests that premedication should be minimized whenever possible and reserved for more severe situations.
In about 10% of people muscle-bone aches can occur 24 hours after the treatment. Some have compared the feeling to a full-body workout and appears to be a sign of the body responding to the iron.
Intravenous iron can also create skin staining if there is leakage or extravasation at or around the injection site. The skin stain can be permanent. This is one of the reasons why the intramuscular use of iron has been discouraged. The risks are uncommon with some estimates reported to be 0.68 to 1.3%. As a result, it is imperative that if any leakage does occur that the IV be stopped immediately and removed just in case.
Formulations of intravenous iron that are capable to be administered more quickly and stronger in dose (i.e., less time on the chair plus reduced treatment visits) could have advantages in this area (i.e., Monoferric). Signs of leakage can include pain, discomfort, swelling, prickling at or around the injection site and any immediately observable staining.
It will be advised to wait approximately 30 minutes following the infusion to assess for any potential delayed reaction.
Baseline blood tests, along with basic levels of assessment, will be required before starting and following your treatment to help determine your candidacy, initial iron dose and your response to treatment.