Iron Infusion Administration Protocol
Iron infusions should be administered using specific protocols based on the formulation, with iron sucrose given as 200 mg IV over 30-60 minutes weekly until the calculated iron deficit is corrected (not exceeding 1000 mg total), while ferric carboxymaltose can be administered as a single dose of up to 1000 mg over 15 minutes. 1
Iron Formulation Selection and Dosing
Iron Sucrose (Venofer)
- Maximum single dose: 200 mg
- Administration time: 30-60 minutes
- Frequency: Weekly until calculated iron deficit is corrected
- Total dose should not exceed 1000 mg 1
- No test dose required (unlike iron dextran) 1
Ferric Carboxymaltose (Injectafer/Ferinject)
- Maximum single dose: 1000 mg (Europe/Asia), 750 mg (US)
- Administration time: 15 minutes for 1000 mg dose 1
- Dilution requirements:
- 500 mg dose: 10 mL FCM in 100 mL normal saline (minimum 6 minutes)
- 1000 mg dose: 20 mL FCM in 250 mL normal saline (minimum 15 minutes) 1
Administration Procedure
Pre-administration assessment:
Preparation:
- For iron sucrose: No specific dilution requirements noted
- For ferric carboxymaltose: Dilute in normal saline according to dosing table 1
- Do not mix with other medications
Administration technique:
- Use a dedicated IV line
- Administer via slow IV infusion at specified rates
- Monitor vital signs before, during, and after infusion
- Observe patient for at least 30 minutes following each IV injection 1
Emergency preparedness:
- Have emergency medications and equipment available to treat potential hypersensitivity reactions
- If paravenous leakage occurs, stop infusion immediately to prevent skin staining 1
Monitoring and Follow-up
- Monitor hemoglobin levels every 4 weeks until normalization
- After hemoglobin normalizes, check complete blood count at 3-month intervals for 12 months, then 6-monthly for 2-3 years 1
- Re-evaluate iron status 3 months after administration (serum ferritin increases markedly following IV iron and cannot be reliably assessed within 4 weeks) 1
- Monitor serum phosphate levels in patients at risk for hypophosphatemia or requiring repeat courses, especially with ferric carboxymaltose 1, 2
- Target values: ferritin >100 μg/L and hemoglobin >12 g/dL 1
Special Considerations
Pediatric Patients
- Ferric carboxymaltose is approved for IDA in patients aged 1 year and older with normal kidney function who have intolerance or unsatisfactory response to oral iron 3
- Not established for children under 1 year of age 3
Geriatric Patients
- No overall differences in safety or effectiveness observed in elderly patients, but greater sensitivity in some individuals cannot be ruled out 3
Adverse Effects to Monitor
- Common (1-10%): Dizziness, headache, hypertension, hypophosphatemia, injection-site reactions, nausea 1
- Less common (0.1-1%): Hypersensitivity reactions 1
- Serious concern with ferric carboxymaltose: Hypophosphatemia (occurs in 50-74% of patients) which can lead to bone pain, osteomalacia, and fractures in severe cases 2
Advantages of IV Iron Over Oral Therapy
- Avoids gastrointestinal side effects common with oral preparations
- Provides more rapid correction of iron deficiency 1
- More effective in patients with ongoing blood loss (e.g., heavy menstrual bleeding) 1
- Clinical trials have shown superior efficacy of ferric carboxymaltose over oral iron in achieving hemoglobin increases ≥1 g/dL (60.4% vs 34.7%) 4
Common Pitfalls and How to Avoid Them
- Failure to calculate correct iron deficit: Use appropriate formulas based on weight and hemoglobin deficit
- Administering too rapidly: Adhere to minimum infusion times to prevent reactions
- Inadequate monitoring: Follow recommended post-infusion observation period of at least 30 minutes
- Misinterpreting early post-infusion ferritin: Wait at least 4 weeks before using ferritin to assess response 1
- Overlooking hypophosphatemia: Monitor phosphate levels, particularly with ferric carboxymaltose 2