What is IVIG?
Intravenous immunoglobulin (IVIG) is a medication derived from pooled plasma of healthy donors, containing antibodies used to treat various conditions like primary immunodeficiency and autoimmune disorders. It works by regulating the immune system or replacing antibodies. While generally safe, IVIG can cause side effects, with fever being frequently reported.
Understanding Infusion-Related Reactions
Reactions to IVIG are often categorized by timing and severity. Fever is a common symptom of a mild, immediate reaction, usually within the first hour of infusion. These flu-like reactions are manageable. They are more likely during the initial infusion or when changing IVIG brands.
Common symptoms of a mild infusion reaction include:
- Fever: Often low-grade and frequent.
- Chills: Feeling cold and shivering.
- Headache: Common mild to moderate headaches.
- Nausea: Feeling sick.
- Muscle aches (myalgia): Body aches and pains.
- Fatigue: Feeling unusually tired.
- Flushing: Warmth or redness of the skin.
Why Does IVIG Cause a Fever?
The exact cause of infusion-related reactions like fever is not fully clear, but several factors are thought to contribute. These reactions are considered a systemic inflammatory response. Potential mechanisms include:
- Cytokine Release: IVIG infusion may trigger the release of cytokines, which can cause fever and flu-like symptoms.
- Complement Activation: Components in the IVIG product might activate the complement system, leading to inflammation.
- Infusion Rate: A faster infusion rate increases the risk of fever and other adverse reactions. Slower rates are often used initially.
- Contaminants: Although rare due to modern manufacturing, trace amounts of aggregates or contaminants could potentially cause a reaction.
Risk Factors for IVIG-Related Fever
Certain individuals may have a higher risk of fever or other infusion reactions. Risk factors include:
- First-Time Treatment: Initial IVIG infusions are more likely to cause a reaction.
- Underlying Infection or Inflammation: Active infections or chronic inflammatory conditions may increase the risk of fever due to a heightened immune response.
- Rapid Infusion Rate: Infusing the product too quickly is a primary cause of adverse reactions.
- Dehydration: Not being well-hydrated can increase side effect risk.
- Previous Reactions: A history of reactions can make future reactions more likely.
- Product Switching: Changing to a different brand of IVIG may trigger a reaction.
Managing a Fever During or After IVIG
Effective management helps minimize discomfort during IVIG therapy. For a mild fever, your healthcare team may use these strategies:
- Slowing or Stopping the Infusion: If a reaction occurs, the infusion rate is immediately slowed or stopped until symptoms improve.
- Premedication: Taking acetaminophen and an antihistamine before infusion can prevent or reduce fever and other reactions.
- Post-Infusion Medication: If fever continues after the infusion, over-the-counter pain relievers like acetaminophen or ibuprofen may be used as directed.
- Hydration: Staying hydrated before, during, and after infusion is important for reducing side effects.
- Monitoring: Vital signs, including temperature, are monitored throughout the infusion. Patients administering at home learn how to monitor for mild reactions.
Seek immediate medical attention for persistent or high fevers (above 101°F) or if accompanied by severe symptoms like a stiff neck or severe headache.
IVIG vs. SCIG: A Comparison
Subcutaneous immunoglobulin (SCIG) is an alternative to IVIG for some patients, infused under the skin and absorbed slowly. This can result in a different side effect profile compared to IVIG.
| Feature | IVIG (Intravenous Immunoglobulin) | SCIG (Subcutaneous Immunoglobulin) |
|---|---|---|
| Route | Intravenous (directly into the bloodstream) | Subcutaneous (under the skin) |
| Infusion Site Reactions | Rare | Common (redness, swelling, itching at site) |
| Systemic Reactions (Fever, Chills) | More frequent and potentially more severe | Less frequent and generally milder |
| Infusion Rate | Generally faster; rapid infusion increases reaction risk | Slower; self-administered over multiple sites |
| First-Dose Reactions | Reactions most common during first dose or with a new brand | Less likely to cause systemic first-dose reactions |
Switching from IVIG to SCIG might be an option for patients with frequent systemic side effects like fever. Your doctor can help determine suitability.
Conclusion
In summary, fever is a common side effect of IVIG, particularly during the first infusion, often occurring as a mild, flu-like reaction with chills and headaches. Working with your healthcare team, using premedication, and staying hydrated can effectively manage or prevent fever and other reactions. Persistent or worsening reactions require communication with your provider. Consult your doctor or reliable resources like the American College of Rheumatology website(https://www.rheumatology.org/patients/intravenous-immunoglobulin-ivig) for more information.
