IVIG Maintenance Dosing for CIDP
The standard maintenance dose of IVIG for CIDP is 1.0 g/kg administered every 3 weeks, following an initial induction regimen of 0.4 g/kg/day for 5 consecutive days (total 2 g/kg). 1
Induction Phase
- Begin with 0.4 g/kg/day for 5 consecutive days (total induction dose: 2 g/kg) 1, 2
- This loading dose establishes initial disease control before transitioning to maintenance therapy 1
Standard Maintenance Regimen
- Administer 1.0 g/kg every 3 weeks as the evidence-based maintenance schedule 1, 2
- This regimen maintains sustained remission in approximately 70% of patients over 52 weeks 1
- At 28 weeks, the responder rate reaches 77.6%, with only 10.5% experiencing relapse by week 52 when maintained on this schedule 1
Duration of Maintenance Therapy
- Most patients (83%) require continuation of maintenance IVIG for at least 18 months 2
- Long-term maintenance prevents relapse, with a 24% relapse rate observed during the 18-month observation period 2
- Approximately 17% of patients achieve continuous remission and may attempt therapy withdrawal after a mean of 136 days, though 24% of these patients subsequently relapse 2
Dose Individualization Considerations
While the standard 1.0 g/kg every 3 weeks is the evidence-based starting point, some patients may require adjustments:
- Dose reductions are possible in all patients (mean reduction: 63.3%, range: 42.4-88% from initial dosing), but this must be done cautiously after establishing stable disease control 3
- The lowest effective maintenance dose varies considerably between patients (18-108 g per course) 3
- Treatment frequency typically cannot be extended beyond 3 weeks in most patients, even when dose is reduced 3
- For patients with very short efficacy windows (<15 days), consider increasing the monthly cumulative dose (up to 3 g/kg/month) with more frequent fractionated dosing 4
Monitoring Strategy
- Assess response using the Inflammatory Neuropathy Cause and Treatment (INCAT) disability score 1, 2
- Define relapse as worsening of INCAT score by ≥1 point from baseline 1, 2
- Monitor serum IgG levels to correlate with clinical response, particularly in patients requiring dose adjustments 4
- Watch for thrombotic complications, especially in elderly patients with vascular risk factors (cerebral infarction occurred in 2 patients aged 66 and 76 years with hypertension or diabetes) 1
Critical Safety Considerations
- Cardiac function evaluation is crucial before administering IVIG, particularly in patients with cardiac dysfunction 5
- One serious adverse drug reaction of cardiac failure has been reported during maintenance therapy 2
- For patients with cardiac dysfunction, consider divided dosing (1 g/kg daily over 2 days) to minimize fluid overload 5
- Check serum IgA levels before initiating IVIG to prevent severe anaphylaxis in IgA-deficient patients 5
Common Pitfall to Avoid
Do not attempt to extend the dosing interval beyond 3 weeks as the primary strategy for dose optimization. Evidence shows that treatment frequency is typically fixed for each patient and cannot be safely prolonged, even when the dose per infusion is reduced 3. Instead, focus on finding the lowest effective dose while maintaining the 3-week interval.