What is the recommended protocol for administering iron infusion to a patient with iron deficiency anemia, considering their medical history and potential allergies?

How to Administer Iron Infusion

Preferred IV Iron Formulations

For most patients requiring IV iron, use ferric carboxymaltose (FCM) or iron sucrose as first-line agents, as they allow rapid repletion without requiring test doses and have superior safety profiles compared to iron dextran. 1, 2

Ferric Carboxymaltose (First Choice)

• Administer 1000 mg IV over 15 minutes when diluted in 250 mL normal saline, or as slow IV push over 15 minutes for the full 1000 mg dose 2
• Maximum single dose: 1000 mg of elemental iron 3
• Maximum weekly dose: 1000 mg 3
• No test dose required 1
• Allows completion of iron repletion in 1-2 infusions 3, 2

Iron Sucrose (Alternative)

• Administer 200 mg IV over 60 minutes (infusion) or 200 mg over 2-5 minutes (slow IV bolus) 1
• Repeat every 2-3 weeks until total required dose achieved 1
• Maximum single dose: 300 mg 1
• Maximum total dose: 1000 mg 1
• No test dose required 1
• Most extensively studied in pediatric patients (approved ≥2 years old) 1

Iron Dextran (Use Only When Others Unavailable)

• Mandatory 25 mg test dose administered as slow IV bolus, wait 1 hour before main dose 1, 4
• Administer 100 mg IV over 5 minutes weekly for 10 doses, or infuse total dose over several hours 1
• Carries black-box warning for anaphylaxis risk 1
• Higher risk of serious hypersensitivity reactions compared to other formulations 1

Ferric Gluconate

• Administer 125 mg IV over 60 minutes weekly for 8 doses 1, 4
• Dilute in 100 mL of 0.9% sodium chloride 4
• Maximum single dose: 125 mg 1
• Maximum total dose: 1000 mg 1
• Test dose of 25 mg recommended at physician discretion for patients with prior sensitivities 1

Pre-Administration Requirements

Patient Screening

• Confirm iron deficiency: ferritin <100 μg/L, or ferritin 100-299 μg/L with transferrin saturation <20% 3
• Exclude active bacteremia—do not administer IV iron during active infection 3, 1
• Screen for prior hypersensitivity to parenteral iron products 4
• Assess for multiple drug allergies, severe asthma, eczema, or atopic conditions (increased hypersensitivity risk) 3
• Avoid in first trimester of pregnancy (before 13 weeks gestation) 2

Facility Requirements

• Personnel trained in recognizing and managing hypersensitivity reactions must be present 2, 4
• Emergency medications (epinephrine, corticosteroids) and resuscitation equipment immediately available 3, 2
• Capability to monitor patients for at least 30 minutes post-infusion 3, 2, 4

Administration Protocol

Dilution and Infusion

• For FCM: Do not over-dilute, as this affects drug stability 3
• For iron sucrose: Dilute in normal saline per dosing protocol 1
• For ferric gluconate: Dilute 125 mg in 100 mL 0.9% sodium chloride 4
• Never mix IV iron with other medications or add to parenteral nutrition solutions 4
• Administer only in 0.9% saline 4

Monitoring During Infusion

• Monitor continuously for signs of hypersensitivity: dyspnea, hypotension, chest pain, angioedema, urticaria 3, 4
• Monitor blood pressure throughout infusion (hypotension is common) 3, 4
• Observe patient for minimum 30 minutes after completion of infusion 3, 2, 4

Management of Infusion Reactions

Recognizing Reaction Types

Most reactions are complement activation-related pseudo-allergy (CARPA), not true anaphylaxis—these resolve without treatment and should not be managed with vasopressors or antihistamines. 3, 2

If Reaction Occurs

• Slow or temporarily stop the infusion 5
• Do NOT administer diphenhydramine—its side effects mimic worsening reactions 2
• True anaphylaxis (rare, <1% of administrations): Treat with IV epinephrine, corticosteroids 3
• Hypotension: Administer 500 mL normal saline bolus 5
• Rechallenge with the same formulation is safe after a CARPA reaction 2

Post-Administration Monitoring

Immediate Follow-Up

• Re-evaluate iron status at 3 months post-infusion 3
• Avoid early re-evaluation within 4 weeks—ferritin levels are artificially elevated and unreliable during this period 3
• Expect hemoglobin increase of 1 g/dL within 2 weeks 2

Target Parameters

• Target ferritin ≥50 ng/mL (some guidelines suggest maintaining 100-800 ng/mL) 3, 2
• Target transferrin saturation ≥20% 3
• Monitor for hypophosphatemia with FCM (occurs in 50-74% of patients) 2

Repeat Dosing

• Provide additional iron repletion as needed based on 3-month reassessment 3
• For chronic conditions (heart failure, CKD): Consider routine screening 1-2 times per year 3

Special Populations

Pediatric Patients (≥6 years)

• Iron sucrose preferred: 0.12 mL/kg (1.5 mg/kg elemental iron) diluted in 25 mL 0.9% sodium chloride, infused over 1 hour 4
• Maximum single dose: 125 mg elemental iron 4
• Administer during dialysis sessions for 8 sequential treatments 4

Chronic Kidney Disease on Hemodialysis

• Maintain TSAT ≥20% and ferritin ≥100 ng/mL 3
• Adjust pro-rated weekly IV iron dose based on TSAT and ferritin monitored every 3 months 3
• Temporarily withhold if TSAT >50% or ferritin >800 ng/mL to avoid overload 3

Heart Failure with Reduced Ejection Fraction

• IV FCM indicated for symptomatic patients with LVEF <40% and iron deficiency 3
• Improves exercise capacity, symptoms, and quality of life 3
• May reduce recurrent hospitalizations 3

Inflammatory Bowel Disease

• Use IV iron for active inflammation with compromised absorption 3
• Oral iron may worsen IBD symptoms 3

Critical Safety Warnings

• Contraindicated in iron overload or disturbances in iron utilization 3
• Stop treatment in patients with ongoing bacteremia 3
• Ferric carboxymaltose causes symptomatic hypophosphatemia more frequently than other formulations 2
• Anaphylaxis is extremely rare (<1%) but potentially fatal—emergency preparedness is mandatory 3
• Iron dextran has highest risk profile and requires mandatory test dose 3, 1