Intravenous Iron Protocol for Iron Deficiency Anemia
For patients requiring intravenous iron supplementation, ferric carboxymaltose is the preferred agent due to its ability to deliver high doses in short infusion times with a favorable safety profile. 1
Patient Selection for IV Iron Therapy
IV iron should be considered first-line treatment in the following scenarios:
- Patients with clinically active inflammatory bowel disease
- Previous intolerance to oral iron
- Hemoglobin below 10 g/dL
- Patients requiring erythropoiesis-stimulating agents
- Ongoing blood loss (e.g., GI bleeding, menorrhagia)
- Symptomatic iron deficiency despite normal hemoglobin 2, 1
Dosing Protocol
Ferric Carboxymaltose (Injectafer/Ferinject) - Preferred Option
Dosing based on hemoglobin and body weight:
| Hemoglobin (g/dL) | Body weight <70 kg | Body weight ≥70 kg |
|---|---|---|
| 10-12 (women) | 1000 mg | 1500 mg |
| 10-13 (men) | 1000 mg | 1500 mg |
| 7-10 | 1500 mg | 2000 mg |
| <7 | 1500 mg + additional 500 mg | 2000 mg + additional 500 mg |
Administration:
- Maximum single dose: 750 mg in US (1000 mg in EU)
- Infusion time: 15 minutes
- For doses >750 mg, administer second dose after at least 7 days 2, 1, 3
Alternative Options
Iron Sucrose (Venofer)
- Maximum single dose: 200 mg
- Infusion time: 10 minutes
- Multiple doses needed to achieve iron repletion 2, 1
Iron Dextran (Cosmofer)
- Maximum single dose: 20 mg/kg
- Infusion time: 6 hours
- Can replenish iron in a single infusion but has higher risk of serious reactions (0.6-0.7%)
- Test dose required due to risk of anaphylaxis 2
Administration Procedure
- Calculate total iron deficit based on hemoglobin and body weight
- Ensure resuscitation facilities are available before administration
- For ferric carboxymaltose:
- Dilute up to 1000 mg in no more than 250 mL of sterile 0.9% sodium chloride
- Ensure concentration is not less than 2 mg iron/mL
- Administer over at least 15 minutes
- Monitor for extravasation (can cause long-lasting brown discoloration)
- Monitor patient for at least 30 minutes after infusion for hypersensitivity reactions 1, 3
Monitoring Parameters
- Hemoglobin: Monitor every 4 weeks until normalization
- Iron status: Re-evaluate 8-12 weeks after completion of therapy
- Target parameters:
- Hemoglobin ≥11-12 g/dL
- Ferritin >100 ng/mL
- Transferrin saturation >20%
- Check serum phosphate in patients receiving repeat courses within 3 months (especially with ferric carboxymaltose) 1
Follow-up Schedule
After achieving normal hemoglobin and iron indices:
- Monitor at 3-month intervals for 1 year
- Then after a further year
- Again if symptoms of anemia develop
- Provide further oral iron if hemoglobin or red cell indices fall below normal 2
Safety Considerations
Contraindications
- Hypersensitivity to the specific iron formulation
- Iron overload or hemochromatosis
- Anemia not attributed to iron deficiency
- Active infection
- Hemoglobin >15 g/dL 1
Adverse Effects to Monitor
- Hypersensitivity reactions (rare but serious)
- Hypophosphatemia (more common with ferric carboxymaltose)
- Infusion site reactions
- Transient hypotension, flushing, headache, dizziness 1, 4
Risk Mitigation
- Discontinue IV iron if transferrin saturation >50% or serum ferritin >800 ng/mL to prevent iron overload
- For patients with history of hypersensitivity to IV iron, consider desensitization protocols
- Monitor for hypophosphatemia, especially with repeated doses of ferric carboxymaltose 1, 5, 4
Clinical Efficacy Considerations
Ferric carboxymaltose demonstrates rapid improvement in hemoglobin levels compared to oral iron, with studies showing 60.4% of patients achieving hemoglobin increase ≥1 g/dL versus 34.7% with oral iron 6. It also shows better tolerability with significantly fewer treatment-related adverse events (2.7% vs 26.2% with oral iron) 6.
While IV iron preparations have a higher acquisition cost, this may be offset by fewer required doses, faster correction of anemia, and reduced healthcare utilization 7.