How to Administer IVIG
Administer IVIG at 1-2 g/kg of ideal body weight over 2 consecutive days for most autoimmune conditions, or 0.4 g/kg daily for 5 days for immunodeficiency replacement therapy, after screening for IgA deficiency and ensuring adequate hydration. 1
Pre-Administration Assessment
Screen for IgA deficiency before the first IVIG infusion to prevent potentially fatal anaphylactic reactions, and use IgA-depleted preparations if deficiency is detected 1, 2. Review the patient's history specifically for:
- Renal dysfunction (creatinine, BUN, hydration status) 1, 2
- Thrombotic risk factors (age >65, diabetes, hypertension, immobility, prior thromboembolism) 2, 3
- Previous infusion reactions 1
- Cardiac dysfunction requiring divided dosing 1
Dosing by Indication
For autoimmune/inflammatory conditions: Use 1-2 g/kg of ideal body weight divided over 2 consecutive days 1. Specific examples:
- ITP (Immune Thrombocytopenic Purpura): 1 g/kg as a single dose, repeatable if needed 4
- Kawasaki Disease: 2 g/kg as a single infusion over 10-12 hours 1, 5
- Guillain-Barré Syndrome: 0.4 g/kg/day for 5 days (total 2 g/kg) 1
For immunodeficiency replacement: Use 300-400 mg/kg IV monthly, adjusting to maintain IgG trough levels >500 mg/dL 1, 6
For obese patients (BMI ≥30): Calculate dose using ideal body weight or adjusted body weight, not actual body weight 1
Premedication Protocol
Administer before starting the infusion 4, 1:
- Acetaminophen (paracetamol) 4, 1
- Diphenhydramine 1
- Corticosteroids (e.g., 20 mg prednisone) for patients with prior infusion reactions or when using higher doses 4, 1
Infusion Setup and Rate
Ensure adequate hydration before starting the infusion, especially in high-risk patients 2, 3. Begin with a slow infusion rate and gradually increase as tolerated 2, 3. The infusion typically takes several hours to complete 4.
For patients with cardiac dysfunction or fluid overload risk, divide the total dose over 2 days (1 g/kg daily) rather than giving as a single infusion 1.
Monitoring During Infusion
Monitor continuously for 1, 2:
- Vital signs (blood pressure, heart rate, temperature)
- Signs of infusion reactions (headache, flushing, chest tightness, fever, chills, nausea)
- Renal function (urine output, serum creatinine) 1
- Anaphylaxis symptoms in IgA-deficient patients 2
Management of Adverse Reactions
For mild reactions (headache, flushing, myalgia): Slow or temporarily stop the infusion, administer analgesics, NSAIDs, or antihistamines 2, 3
For severe reactions (anaphylaxis, severe hypotension, chest pain):
- Immediately stop the infusion 1
- Administer epinephrine for anaphylaxis 1
- Notify physician immediately 1
- Do not restart until evaluated 2
Post-Infusion Care
- Continue monitoring renal function for 24-48 hours 1, 2
- Assess clinical response based on indication (e.g., platelet count for ITP within 24 hours to 2-4 days) 4, 5
- Watch for delayed complications: thromboembolism, aseptic meningitis (headache, neck stiffness), hemolytic anemia 4, 2
Critical Pitfalls to Avoid
Never use intramuscular immunoglobulin preparations intravenously—only products specifically modified for IV use can be given intravenously 4. Avoid sucrose-containing products in patients with renal insufficiency due to osmotic injury risk 2, 3. Do not administer IVIG before therapeutic plasma exchange, as it will be removed; give it after plasma exchange is completed 7.