What is the recommended intravenous (IV) iron preparation and dosage for a patient with iron deficiency anemia?

IV Iron Administration for Iron Deficiency Anemia in Indian Clinical Practice

For iron deficiency anemia in India, administer ferric carboxymaltose (Ferinject) 750-1000 mg IV over 15 minutes as the preferred first-line option, or alternatively use iron sucrose 200 mg IV over 10 minutes (requiring multiple doses). 1, 2

Which IV Iron Preparation to Use in India

Ferric carboxymaltose (FCM) is the optimal choice because:

• Can deliver 750-1000 mg in a single 15-minute infusion 1, 2
• No test dose required 1
• Allows complete iron repletion in 1-2 visits 3, 4
• Excellent safety profile with anaphylaxis risk <1:250,000 1

Iron sucrose is a widely available alternative in India:

• Maximum 200 mg per dose over 10 minutes 1
• No test dose required 1
• Requires 5-7 doses for complete repletion 5
• Lower cost but more hospital visits 1

Avoid high molecular weight iron dextran (Dexferrum) - it has been removed from markets due to high adverse reaction rates 1

Low molecular weight iron dextran (Infed) can be used if cost is the primary concern:

• Allows single-dose infusion >1000 mg 1
• Mandatory test dose required due to anaphylaxis risk (0.6-0.7%) 1
• Lowest cost option 1

Dosing Calculations

For Iron Deficiency Anemia (Hemoglobin <12 g/dL women, <13 g/dL men):

Use the Ganzoni formula to calculate total iron deficit: 3

• Body weight (kg) × [target Hb - actual Hb (g/dL)] × 0.24 + 500 mg

Standard dosing approach:

• Patients ≥50 kg: 1000-1500 mg total iron 3, 2
• Patients <50 kg: 15 mg/kg body weight 2
• If Hb <7.0 g/dL: Add additional 500 mg beyond calculated dose 3

Specific Regimens by Preparation:

Ferric carboxymaltose (FCM): 2

• Patients ≥50 kg: 750 mg IV on Day 1, repeat 750 mg after 7 days (total 1500 mg)
• Alternative: Single dose of 1000 mg IV (15 mg/kg, max 1000 mg)
• Patients <50 kg: 15 mg/kg IV on Day 1, repeat after 7 days

Iron sucrose: 1

• 200 mg IV over 10 minutes
• Repeat 2-3 times weekly until total calculated dose achieved
• Typically requires 5-7 doses for complete repletion

Low molecular weight iron dextran (Infed): 1

• Mandatory test dose: 25 mg IV over 5 minutes, observe 1 hour
• If no reaction: Infuse total calculated dose (up to 20 mg/kg) over 6 hours
• Single-dose total replacement possible

Administration Technique

Preparation:

• FCM: Can give undiluted as slow IV push (100 mg/2 mL per minute) OR dilute up to 1000 mg in 250 mL normal saline (minimum concentration 2 mg/mL) 2
• Iron sucrose: Dilute 200 mg in 100 mL normal saline 1
• Inspect for particulate matter before administration 2

Infusion Protocol:

• FCM 750-1000 mg: Infuse over 15 minutes 1, 2, 4
• Iron sucrose 200 mg: Infuse over 10 minutes 1
• Iron dextran: Infuse total dose over 6 hours after test dose 1

Safety Requirements:

• Resuscitation equipment must be immediately available for all IV iron administrations 1
• Monitor patient during infusion and for 30 minutes post-infusion 1
• Avoid extravasation - causes long-lasting brown skin discoloration 2
• If extravasation occurs, stop infusion immediately and restart at different site 2

Critical Contraindications and Precautions

Do NOT give IV iron if: 1

• Active bacterial infection present
• Known anaphylaxis to the specific iron preparation

Test dose mandatory for: 1

• Low molecular weight iron dextran (Infed) - always required
• Ferric gluconate or iron sucrose - if patient has drug allergies or previous iron sensitivity

Monitor serum phosphate levels: 2

• Check before repeat dosing within 3 months
• FCM can cause severe hypophosphatemia (50-74% of patients) 6
• May lead to bone pain, osteomalacia, fractures if untreated 6

Expected Response and Follow-up

Acceptable hematologic response: 3

• Hemoglobin increase ≥2 g/dL within 4 weeks
• More rapid rise with IV iron versus oral (7 days vs 14 days) 7

Monitoring schedule: 1, 3

• Recheck hemoglobin, ferritin, transferrin saturation at 4 weeks
• If target not achieved, investigate for ongoing blood loss or other causes
• Once normalized: Monitor every 3 months for 1 year, then annually

Retreatment criteria: 3, 2

• Serum ferritin drops <100 ng/mL
• Hemoglobin falls below gender-specific thresholds
• Transferrin saturation <20% with ferritin 100-300 ng/mL

Common Pitfalls to Avoid

Do not recheck iron studies immediately after IV iron - ferritin falsely elevated for 8-10 weeks 1

Do not exceed upper safety limits: 3

• Transferrin saturation >50%
• Serum ferritin >800 ng/mL

Do not give IV iron during active infection - theoretical risk of promoting bacterial growth 1

Do not use oral iron concurrently - no additional benefit and increases side effects 1

Most common adverse effects: 1, 4

• Headache, dizziness, nausea (mild-moderate severity)
• Hypotension, flushing during infusion
• Injection site reactions with FCM more common than oral iron
• True anaphylaxis is rare (<1%) with modern preparations 1, 6