What is the protocol for administering iron infusions in adult patients with iron deficiency anemia, including pretreatment, precautions, potential side effects, and post-infusion care?

Iron Infusion Administration Protocol

All staff administering IV iron must be properly trained in recognizing and managing infusion reactions, with resuscitation facilities and medications immediately available, as anaphylaxis can occur with any parenteral formulation. 1

Pre-Treatment Assessment

Risk Stratification

• Assess high-risk features before infusion: history of severe asthma, eczema, mastocytosis, multiple drug allergies, or prior reaction to IV iron 1
• No routine premedication or test doses are necessary for modern non-dextran formulations, as premedication is associated with 23-fold higher adverse event rates without proven benefit 2
• For iron dextran specifically: monitor for 60 minutes after initial dose with resuscitation facilities available 1

Contraindications and Cautions

• Withhold during active bacteremia but infection alone is not a contraindication if risk/benefit favors treatment 1
• Avoid in patients with active malignancy where cure is anticipated, though this applies more to ESA therapy context 1

Infusion Administration

Initiation Protocol

• Start infusion at slow rate as slower rates are associated with lower reaction incidence 1
• Observe closely during first 10 minutes when immediate reactions typically occur 1
• Monitor vital signs: blood pressure, pulse, respiratory rate, oxygen saturation, temperature 1
• Switch IV line to normal saline at keep-vein-open rate if any acute symptoms develop 1

Formulation-Specific Dosing

Modern total-dose formulations (preferred):

• Ferric carboxymaltose: 1000 mg over 15 minutes in single infusion 1, 3
• Iron derisomaltose: 1000 mg over 15-40 minutes 1, 3
• Iron dextran: 20 mg/kg over 6 hours (rarely used due to inconvenience) 1

Multiple-dose formulations:

• Iron sucrose: maximum 200 mg over 10 minutes, requires 4-7 visits for complete repletion 1, 3
• Iron gluconate: 62.5-125 mg over 30-60 minutes 1

Infusion Reaction Management

Mild Reactions (pruritus, flushing, urticaria, chest tightness, back pain, joint pain)

• Stop infusion immediately and notify physician 1
• Monitor for ≥15 minutes with IV normal saline at keep-vein-open rate 1
• Consider hydrocortisone 100-500 mg IV 1
• Consider famotidine 20 mg IV 1

Moderate Reactions (mild symptoms plus transient cough, shortness of breath, tachycardia, hypotension with SBP drop ≥30 mmHg or SBP ≤90 mmHg)

• Treat as mild HSR plus additional measures 1
• If hypotensive: recline patient and administer 1000-2000 mL normal saline bolus 1
• If hypoxemic: provide oxygen by mask or nasal cannula 1

Severe/Anaphylaxis (sudden onset, loss of consciousness, severe hypotension, angioedema of tongue/airway, multi-organ involvement)

• Immediately call emergency services or resuscitation team 1
• Administer epinephrine 0.3 mg IM into anterolateral mid-thigh, may repeat once 1
• Consider albuterol 0.083% via nebulizer for bronchospasm 1
• Treat individual symptoms: ondansetron 4-8 mg IV for nausea, antihistamines for urticaria 1

Rechallenge Protocol

• After symptom resolution: discuss with patient and restart infusion ~15 minutes later at 50% of initial rate 1
• If well tolerated: increase slowly after 15 minutes 1
• Stop if symptoms recur 1
• For patients with prior reactions: switching to alternate formulation reduces reaction rate from 68% to 5% compared to same formulation with premedication 2

Post-Infusion Care

Immediate Monitoring

• Continue vital sign monitoring until stable after infusion completion 1
• Observe for delayed reactions which are uncommon with doses ≤200 mg but can occur with larger doses 1

Patient Education

• Educate on delayed reactions: flu-like symptoms, arthralgias, myalgias, fevers typically managed with NSAIDs 1
• Delayed arthralgia-myalgia syndrome occurs in up to 59% with total dose infusions but rarely with doses ≤100 mg 1

Follow-Up Monitoring

• Check hemoglobin in 4-8 weeks: expect 1-2 g/dL increase 3
• Monitor phosphate levels in patients receiving ferric carboxymaltose (58% hypophosphatemia risk) or those with risk factors for hypophosphatemia 1, 4
• Iron parameters (TSAT, ferritin): recheck at least every 3 months during ongoing therapy 1
• Avoid measuring iron parameters for 2 weeks after doses ≥1000 mg or 7+ days after 200-500 mg doses for accurate assessment 1

Common Pitfalls to Avoid

• Do not use premedication routinely as it increases adverse event rates without benefit 2
• Do not use test doses for non-dextran formulations as they are unnecessary and delay treatment 2
• Do not readminister same formulation after reaction without considering alternate formulation which has significantly lower repeat reaction rates 2
• Do not give iron sucrose >200 mg per dose due to increased labile free iron and unacceptable reaction rates 3
• Overall adverse event rate is 3.9% with severe reactions requiring epinephrine exceedingly rare (0.006%) 2