1. What is IVIG to SCIG Conversion?

The IVIG to SCIG conversion calculator helps determine the equivalent subcutaneous immunoglobulin (SCIG) dose when transitioning from intravenous immunoglobulin (IVIG) therapy. The conversion accounts for differences in bioavailability and administration frequency between the two routes.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( IVIG\ Dose \) — Current intravenous immunoglobulin dose in grams
• \( Adjustment\ Factor \) — Typically ranges from 1.3 to 1.7 (default 1.53)

Explanation: The adjustment factor compensates for the higher bioavailability and more frequent administration of SCIG compared to IVIG.

3. Importance of Conversion

Details: Accurate conversion is crucial for maintaining therapeutic immunoglobulin levels when transitioning from IV to SC administration, preventing both underdosing and excessive dosing.

4. Using the Calculator

Tips: Enter the current IVIG dose in grams and the appropriate adjustment factor (typically 1.53 unless otherwise specified by the clinician). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is an adjustment factor needed?
A: The adjustment accounts for differences in bioavailability and administration frequency between IV and SC routes.

Q2: What's the typical adjustment factor?
A: Most protocols use 1.53, but this may vary based on the specific product and patient factors.

Q3: How often is SCIG administered compared to IVIG?
A: SCIG is typically given weekly or more frequently, while IVIG is usually given every 3-4 weeks.

Q4: Are there clinical advantages to SCIG?
A: SCIG offers more stable IgG levels, fewer systemic side effects, and can be self-administered at home.

Q5: Should this conversion be used for all patients?
A: The conversion should be individualized based on clinical response and trough IgG levels.