- Because most acute reactions to IV iron are complement-activation (non-IgE) events, not true allergic reactions.
- When the infusion is stopped, complement activation rapidly subsides and symptoms (flushing, chest tightness, myalgia) usually resolve within minutes.
- Since there’s no ongoing immune sensitization, the infusion can often be restarted slowly from the same bag once the patient is symptom-free and stable, typically at half the previous rate with close monitoring.
- This would never be done after a true anaphylactic (IgE-mediated) reaction, where the drug must be permanently discontinued.
If a patient has a mild reaction to IV iron, isn’t the problem in the bag? Shouldn’t I change bags or lots before restarting?
- No. These mild reactions are not caused by contamination or a bad bag, but by a transient immune response in the patient—specifically, complement activation triggered by nanoparticles of iron entering the circulation too quickly.
- Once the infusion is stopped, this reaction rapidly settles, and restarting slowly from the same bag is safe because the drug itself isn’t “faulty.”
- Changing the bag or lot won’t prevent the reaction; what matters is the infusion rate and careful monitoring.
- If the reaction were allergic (IgE-mediated) or severe, then the infusion would be permanently stopped and not restarted at all—regardless of bag or lot.