Ivig

# IvIg ## Overview - **Classification**: Immunoglobulin; Blood product - **Mechanism**: Provides broad-spectrum IgG antibodies. Modulates immune response through various anti-inflammatory and immunomodulatory effects. ## Primary Indications 1. **Primary Immunodeficiency (PID)** - Replacement therapy for antibody deficiency. 2. **Immune Thrombocytopenic Purpura (ITP)** - To raise platelet counts and prevent bleeding. 3. **Kawasaki Disease** - To reduce the incidence of coronary artery aneurysms. 4. **Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)** - Immunomodulation for autoimmune neuropathies. ## Adult Dosing ### Standard Dosing **Primary Immunodeficiency (PID)** - **Dose**: **300-800 mg/kg** - **Frequency**: Every **3-4 weeks** - **Route**: IV infusion - **Special Considerations**: Adjust dose/interval based on IgG trough levels and clinical response. **Immune Thrombocytopenic Purpura (ITP)** - **Dose**: **400 mg/kg/day** - **Frequency**: For **2-5 consecutive days** - **Route**: IV infusion - **OR Dose**: **800-1000 mg/kg** - **Frequency**: Single dose (may repeat once if needed) - **Route**: IV infusion **Kawasaki Disease** - **Dose**: **2 g/kg** - **Frequency**: Single dose - **Route**: IV infusion - **Duration**: Infused over **10-12 hours** to optimize tolerability. ### Dose Adjustments - **Renal Impairment**: No specific dose adjustment, but infuse at **minimum rate**. Avoid high-dose regimens if possible. Monitor renal function closely. - **Hepatic Impairment**: No specific dose adjustment typically needed. - **Elderly Patients**: Start with **slower infusion rates**. Monitor closely for fluid overload, renal dysfunction, and thrombotic events. ## Pediatric Dosing ### General Considerations - Initial infusion rate should always be slow and gradually increased if tolerated. - Ensure adequate hydration before and during infusion. ### Neonates (0-28 days) - **Indication Examples**: Neonatal alloimmune thrombocytopenia (NAIT), severe infections (adjunctive). - **Dose**: **500-1000 mg/kg** - **Frequency**: Single dose (e.g., NAIT) or once weekly. - **Maximum**: **1000 mg/kg/dose**. - **Special Notes**: Monitor closely for fluid overload, renal dysfunction, and hyperviscosity. ### Infants (1-12 months) - **Indication Examples**: Kawasaki disease, ITP, Primary Immunodeficiency (PID). - **PID Dose**: **300-800 mg/kg** - **PID Frequency**: Every **3-4 weeks** - **ITP Dose**: **400 mg/kg/day** for **2-5 days** OR **800-1000 mg/kg** single dose. - **Kawasaki Dose**: **2 g/kg** single dose. - **Maximum**: **2 g/kg/dose**. - **Special Notes**: Ensure adequate hydration. Closely monitor for infusion reactions and vital signs. ### Children (1-12 years) - **Indication Examples**: PID, ITP, Kawasaki, etc. - **Dose**: Generally **same mg/kg doses as infants**. - **PID Dose**: **300-800 mg/kg** every **3-4 weeks**. - **ITP Dose**: **400 mg/kg/day** for **2-5 days** OR **800-1000 mg/kg** single dose. - **Kawasaki Dose**: **2 g/kg** single dose. - **Maximum**: **2 g/kg/dose** (for acute indications). - **Special Notes**: Monitor for signs of aseptic meningitis syndrome (headache, neck stiffness, photophobia). ### Adolescents (13-18 years) - **Dose**: Generally follows **adult dosing guidelines**. - **Maximum**: **2 g/kg/dose** (for acute indications) or **80 g/dose** for very large adolescents. ## Safety Information ### Contraindications - **Absolute**: Prior severe anaphylactic reaction to IVIg. - **Absolute**: Selective IgA deficiency with documented antibodies to IgA. - **Relative**: Severe hyperprolinemia (for IvIg products containing proline as stabilizer). ### Common Adverse Effects - **Very Common (>10%)**: Headache, chills, fever, flushing, fatigue. - **Common (1-10%)**: Nausea, vomiting, back pain, myalgia, dizziness, rash. - **Serious but Rare**: Anaphylaxis, aseptic meningitis, acute renal failure, thrombotic events (e.g., stroke, MI, DVT/PE), hemolytic anemia, TRALI. ### Key Drug Interactions - **Live Attenuated Vaccines (MMR, Varicella)**: IvIg may impair efficacy. Defer vaccination for **at least 3 months (up to 11 months)** after IvIg. - **Loop Diuretics**: May increase risk of renal toxicity when used concurrently; monitor renal function. - **Nephrotoxic Drugs**: Concurrent use increases risk of acute renal failure. ## Monitoring & Follow-up - **Before Treatment**: Baseline renal function (BUN/Cr), hydration status, IgA levels (if IgA deficiency suspected), CBC. - **During Treatment**: Vital signs (BP, HR, Temp) before, during, and after infusion. Monitor urine output, signs of infusion reaction, fluid balance. - **Clinical Signs**: Watch for headache, fever, chills (infusion reaction), rash, signs of thrombosis (pain, swelling, neurological changes), decreased urine output. ## Clinical Pearls - 💡 **Infusion Rate**: Start with the slowest recommended infusion rate. Gradually increase if tolerated to minimize infusion-related reactions. Pre-medicate (acetaminophen, antihistamines) for patients with a history of reactions. - 💡 **Hydration**: Ensure patients are well-hydrated before and during infusion to reduce the risk of renal complications and thrombotic events. - 💡 **Renal Risk**: Higher in elderly, those with pre-existing renal impairment, diabetes, volume depletion, and concurrent nephrotoxic drugs. Use lowest effective dose and slowest infusion rate in these populations. - 💡 **Vaccine Impact**: Counsel patients/parents that IvIg can blunt the immune response to live vaccines, requiring delayed administration. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.