What is the recommended medication and protocol for an iron infusion?

IV Iron Infusion: Recommended Medications and Administration Protocols

For iron deficiency anemia requiring IV iron, ferric carboxymaltose (Ferinject/Injectafer) is the preferred formulation as it allows total dose infusion of up to 1000 mg in just 15 minutes, minimizing patient visits while maintaining excellent safety and efficacy. 1, 2

Indications for IV Iron Over Oral Therapy

IV iron should be used when: 1

• Patients cannot tolerate oral iron due to gastrointestinal side effects
• Oral iron fails to correct anemia (hemoglobin should increase by 1 g/dL within 2 weeks of oral supplementation) 1
• Malabsorption conditions exist (inflammatory bowel disease, post-bariatric surgery, celiac disease) 1
• Iron loss exceeds what oral supplementation can replace 1
• Chronic kidney disease patients requiring erythropoietin therapy 1

Recommended IV Iron Formulations

First-Line Options for Total Dose Infusion (Single Visit)

Ferric carboxymaltose (Ferinject/Injectafer) is optimal for most patients: 1, 2

• Patients ≥50 kg: 750 mg IV in two doses separated by at least 7 days (total 1,500 mg per course), OR 15 mg/kg up to maximum 1,000 mg as single dose
• Patients <50 kg: 15 mg/kg IV in two doses separated by at least 7 days
• Administration: 15-minute infusion when diluted in 250 mL normal saline (concentration ≥2 mg iron/mL), or as slow IV push over 15 minutes for 1,000 mg dose 2

Alternative total dose infusion formulations (when ferric carboxymaltose unavailable): 1

• Low molecular weight iron dextran (LMWID): 1,000 mg single infusion
• Ferric derisomaltose (FDI): 1,000 mg single infusion
• Ferumoxytol: 510-1,020 mg (can give 1,020 mg as single dose in 30 minutes) 1

Suboptimal Formulations Requiring Multiple Visits

These require 4-7 visits for complete iron repletion: 1

• Iron sucrose (Venofer): 200 mg maximum per dose, 10-minute infusion 1
• Ferric gluconate: 125 mg maximum per dose 1

Critical Safety Protocols

Pre-Administration Requirements

Essential safety measures that must be in place: 1, 3, 2

• Personnel trained in recognizing and managing hypersensitivity reactions present
• Emergency medications and resuscitation equipment immediately available
• Capability to monitor patients for at least 30 minutes post-infusion 3, 2

Monitoring During and After Infusion

Observe patients for hypersensitivity reactions for at least 30 minutes after completion and until clinically stable. 2 However, routine 30-minute observation for all patients is not indicated—this should be risk-stratified. 1

Managing Infusion Reactions

Most reactions are complement-activated related pseudo-allergy (CARPA), not true anaphylaxis (which occurs in <1:200,000 administrations): 1

• Mild reactions: Stop infusion, restart after 15 minutes at slower rate 1
• Moderate reactions: May benefit from corticosteroids 1
• Avoid diphenhydramine: Its side effects can mimic worsening reactions 1
• Rechallenge with same formulation is safe after a reaction 1

Special Considerations and Pitfalls

Hypophosphatemia Risk with Ferric Carboxymaltose

Critical warning: Ferric carboxymaltose causes symptomatic hypophosphatemia in 50-74% of patients: 4

• Monitor serum phosphate in patients requiring repeat courses within 3 months 2
• Can cause severe complications including bone pain, osteomalacia, and fractures 4
• Other formulations have significantly lower hypophosphatemia risk 1

Contraindications

Do not administer IV iron: 3, 2

• During active bacteremia 3
• In patients with prior hypersensitivity to the specific formulation 2
• In first trimester of pregnancy (avoid before 13 weeks gestation) 1

Dosing Errors to Avoid

Common pitfalls: 1, 2

• Do not dilute ferric carboxymaltose to <2 mg iron/mL (causes instability) 2
• Do not exceed 200 mg per dose for iron sucrose or 125 mg for ferric gluconate 1
• Allow 30 minutes between IV iron and other medications in high-risk patients 1
• Avoid extravasation—causes long-lasting brown discoloration 2

Laboratory Timing After Administration

Wait appropriate intervals before checking iron parameters: 3

• Doses 100-125 mg: Can measure immediately 3
• Doses 200-500 mg: Wait at least 7 days 3
• Doses ≥1,000 mg: Wait at least 2 weeks 3

Follow-Up and Repeat Dosing

Monitor response and iron stores: 1

• Hemoglobin should increase by 1 g/dL within 2 weeks 1
• Check hemoglobin and red cell indices at 3 months, then 3-monthly for 1 year 1
• Target ferritin ≥50 ng/mL regardless of sex 1
• Repeat treatment if iron deficiency recurs 2

Premedication Strategy

Premedication is NOT routinely recommended—reserve only for patients at high risk of hypersensitivity reactions based on prior history. 1 Universal premedication is unnecessary given the excellent safety profile of modern formulations.