How many 200‑mg intravenous iron sucrose (iron sucrose) infusions are needed to raise hemoglobin from 9 g/dL to 12 g/dL in a 70‑kg adult?

Iron Sucrose Dosing to Raise Hemoglobin from 9 to 12 g/dL

For a 70-kg adult with hemoglobin of 9 g/dL targeting 12 g/dL, you need approximately 5 doses of 200-mg iron sucrose (total 1000 mg) given over 2 weeks, with hemoglobin expected to rise by at least 2 g/dL within 4 weeks of completing therapy. 1, 2

Calculating Total Iron Deficit

Use the Ganzoni Formula to determine total iron needed:

• Body weight (kg) × [target Hb - actual Hb (g/dL)] × 0.24 + 500 mg for storage 1
• For this 70-kg patient: 70 × (12 - 9) × 0.24 + 500 = 1,004 mg total iron needed 1

Simplified approach for patients ≥50 kg:

• Hemoglobin 10-12 g/dL (women) or 10-13 g/dL (men): 1000-1500 mg total 1
• Hemoglobin 7-10 g/dL: 1500-2000 mg total 1
• Add 500 mg if Hb <7.0 g/dL 1

Since this patient has Hb of 9 g/dL, the recommended total dose falls in the 1000-1500 mg range, making 5 doses of 200 mg (1000 mg total) the standard regimen. 1

Number of Iron Sucrose Infusions Required

Standard dosing protocol:

• Maximum single dose: 200 mg 1, 3
• Standard regimen for non-dialysis patients: 5 doses of 200 mg over 14 days (total 1000 mg) 1
• Each 200-mg dose infused over 2 hours is safe and well-tolerated 3

If higher total dose needed:

• 1500 mg total requires 7-8 rounds of 200 mg 1
• 2000 mg total requires 10 rounds of 200 mg 1

The 200-mg and 300-mg doses administered over 2 hours have proven safe in systematic studies, while 400-mg and 500-mg doses showed unacceptably high adverse event rates (hypotension, nausea, lower back pain). 3

Expected Hemoglobin Response

Timeline and magnitude of response:

• Hemoglobin should increase by at least 2 g/dL within 4 weeks after completing the 5-dose regimen 1, 2
• Mean hemoglobin rise in clinical studies: 3.29 g/dL for women and 4.58 g/dL for men 2
• Response rate (≥2 g/dL increase): 84% in women, 94% in men 2
• Correction of anemia achieved in 68-71% of patients 2

In one study of 86 adults, mean hemoglobin rose from 8.54 g/dL pre-treatment to 12.1 g/dL post-treatment (p<0.0001), demonstrating that the standard 1000-mg total dose effectively raises hemoglobin by approximately 3.5 g/dL. 2

Administration Protocol

Infusion details:

• Dilute 200 mg in appropriate volume of normal saline 1
• Infuse over 2 hours for maximum safety 3
• Administer doses 2-3 times per week until total calculated dose is given 1, 4
• Resuscitation equipment must be immediately available during all infusions 1

Critical safety considerations:

• Never exceed 200 mg per single infusion 1, 3
• Do not give during active bacterial infection 1
• Do not administer oral iron simultaneously with IV iron 1

Monitoring and Reassessment

Timing of laboratory follow-up:

• Recheck hemoglobin, ferritin, and transferrin saturation at 4 weeks after the final infusion 1
• Do not check iron parameters earlier than 4 weeks, as circulating iron falsely elevates assay results 1

Targets and next steps:

• Expected response: Hb increase ≥2 g/dL within 4 weeks 1
• Do not exceed transferrin saturation >50% or ferritin >800 μg/L 1
• If target not achieved, investigate for ongoing blood loss or other causes of anemia 1

Common Pitfalls to Avoid

The most frequent error is premature discontinuation:

• Stopping after 2-3 doses when patients need 5+ rounds to fully replete iron stores 1
• Always calculate total iron deficit before starting treatment 1

Monitoring errors:

• Checking iron studies too early (<4 weeks) yields falsely elevated ferritin 1
• Failing to reassess at 4 weeks to confirm adequate response 1

Comparison with Other IV Iron Formulations

While iron sucrose requires 5 infusions of 200 mg each, newer formulations offer different dosing:

• Ferric carboxymaltose: 1-2 infusions of 750-1000 mg (total 1500 mg for Hb <10 g/dL) 5
• Ferric derisomaltose: 1-2 infusions of 1000 mg 6

However, iron sucrose has the lowest hypophosphatemia rate (≈1%) compared to ferric carboxymaltose (≈58%), making it safer for patients requiring repeat courses. 5 The trade-off is convenience: iron sucrose requires more clinic visits but has a superior safety profile for phosphate homeostasis. 5

For cancer-related or chemotherapy-induced anemia, intravenous iron (including iron sucrose at 200 mg every 3 weeks) combined with erythropoiesis-stimulating agents produces superior hemoglobin responses compared to oral iron or no iron. 7