Common Side Effects of Iron Infusions
Iron infusions commonly cause side effects including hypotension, nausea, vomiting, diarrhea, pain, hypertension, dyspnea, pruritus, headaches, and dizziness, with most reactions being mild and self-limited. 1
Most Common Adverse Reactions
- Nausea (7.2% of patients receiving ferric carboxymaltose) 2
- Hypertension (4% of patients) - may include transient elevations in systolic blood pressure, sometimes with facial flushing 2
- Flushing (4% of patients) - often occurs immediately after dosing and resolves within 30 minutes 2
- Injection site reactions (3% of patients) - including pain, irritation, bruising, and discoloration 2
- Hypophosphatemia (2.1-27% of patients) - transient decreases in blood phosphorus levels have been observed 2
- Dizziness (2.1% of patients) 2
- Vomiting (2% of patients) 2
Differences Between Iron Preparations
- Most adverse events associated with iron dextran occur with high-molecular-weight iron dextran (Dexferrum) 1
- Low-molecular-weight iron dextran (INFed) is recommended if iron dextran is used 1
- Newer iron compounds (iron sucrose, iron gluconate, iron carboxymaltose) generally have fewer adverse effects than iron dextran 1
- Test doses are required for iron dextran but only recommended for ferric gluconate and iron sucrose in patients with previous sensitivities or multiple drug allergies 1
Serious Adverse Reactions
- Hypersensitivity reactions - rare but potentially life-threatening 3
- Anaphylactic/anaphylactoid reactions - more common with iron dextran than newer formulations 1
- Symptomatic hypophosphatemia - can lead to osteomalacia and fractures in severe cases, especially after repeated exposure 2
- Laboratory test alterations - in the 24 hours following administration, laboratory assays may overestimate serum iron and transferrin bound iron 2
Risk Factors for Adverse Reactions
- Previous reaction to an iron infusion 3
- Fast iron infusion rate 3
- Multiple drug allergies 3
- Severe atopy 3
- Systemic inflammatory diseases 3
- Active infection (patients with active infection should not receive IV iron therapy) 1
- Collagen diseases (increased incidence of adverse effects reported) 1
Prevention and Management of Side Effects
- Administer test doses as recommended for specific preparations 1
- Use slower infusion rates if reactions occur 4
- Monitor patients for signs and symptoms of hypertension following each administration 2
- For hypotension reactions, normal saline infusion may be effective 4
- Check serum phosphate levels in patients at risk for low serum phosphate and before repeat courses of therapy 2
- Ensure administration occurs in settings with resuscitation facilities available 5
Important Caveats
- Most side effects are mild and self-limited 1, 4
- Severe reactions typically occur in a minority of patients and often with larger iron doses 1
- The risk of serious hypersensitivity reactions with newer IV iron preparations is very low (38 incidents per million administrations) 1
- Complement activation-related pseudo-allergy triggered by iron nanoparticles is likely a more frequent mechanism in acute reactions than IgE-mediated responses 3
- Patients should be monitored closely during and after infusion, particularly during the first 30 minutes 2, 6