How Do You Feel After an Immunoglobulin Infusion?

October 13, 2025 •

4 min read

According to a 2018 Immune Deficiency Foundation survey, 98% of patients using IVIG reported experiencing side effects, highlighting that it is very common to have a reaction to the treatment. Understanding how do you feel after an immunoglobulin infusion is crucial for managing expectations and working with your healthcare team to mitigate potential discomfort.

Quick Summary

An immunoglobulin infusion can cause various side effects, including immediate flu-like symptoms, delayed fatigue, and site reactions. Most adverse effects are mild and manageable with premedication or infusion rate adjustments. Rarely, serious reactions like aseptic meningitis or blood clots can occur, necessitating prompt medical attention.

Key Points

Fatigue is a common side effect: Feeling tired or weak is one of the most frequently reported symptoms after an immunoglobulin infusion.
Headaches are highly common: Mild to severe headaches are a frequent reaction, particularly with IVIg infusions.
Hydration helps manage symptoms: Drinking plenty of fluids before, during, and after your infusion is key to reducing the severity of side effects.
Know the difference between IVIg and SCIg reactions: IVIg tends to cause more systemic, flu-like reactions, while SCIg is more associated with local injection site issues.
Monitor for serious reactions: Be aware of rare but serious side effects like aseptic meningitis, blood clots, and kidney issues, and know when to seek immediate medical attention.
Premedication can help: Taking medication like acetaminophen or antihistamines as directed by your doctor before an infusion can help prevent or lessen side effects.
The infusion rate can be adjusted: If side effects occur during the infusion, a healthcare professional can often slow the rate to alleviate symptoms.

Common Side Effects of Immunoglobulin Infusion

After receiving an immunoglobulin (Ig) infusion, a wide range of reactions can occur, from mild and temporary discomfort to more serious, though rare, complications. The majority of patients tolerate the therapy well, but experiencing some side effects is common, particularly during or shortly after the infusion.

Immediate Post-Infusion Reactions

Many side effects, often referred to as infusion-related reactions, typically appear within the first few hours of the treatment. These are frequently linked to the speed of the infusion or the body's reaction to the new antibodies.

Common immediate reactions include:

Headache: This is one of the most frequently reported side effects and can range from mild to severe.
Flu-like symptoms: This can include chills, fever, and general malaise.
Fatigue: A feeling of tiredness or weakness is a very common response.
Nausea and vomiting: These are possible side effects for some individuals.
Muscle or joint aches: Myalgia and arthralgia can occur, sometimes leading to back pain.
Flushing: A reddening of the skin can be a reaction, often due to changes in blood pressure.
Injection site reactions (SCIg): For subcutaneous infusions, local side effects like redness, swelling, and itching are common at the needle site.

Delayed and Longer-Term Effects

Some symptoms may not manifest until several hours or even a few days after the infusion is complete. For patients with regular infusion schedules, a "wear-off" effect is also possible, where symptoms of their underlying condition return as the immunoglobulin levels decrease.

Lingering fatigue: The post-infusion tiredness can persist for a day or two as your body processes the treatment.
Aseptic Meningitis: A rare but serious inflammatory reaction of the brain lining, typically occurring 12 to 48 hours after infusion. Symptoms include severe headache, stiff neck, and sensitivity to light.
Wear-off effect: For chronic conditions, some patients notice increased fatigue, pain, or susceptibility to infection in the days leading up to their next scheduled infusion.

IVIg vs. SCIg: A Comparison of Side Effects

The method of immunoglobulin administration can significantly influence the type and severity of side effects experienced. Intravenous (IVIg) and subcutaneous (SCIg) infusions have distinct side effect profiles. The choice between them is a personalized medical decision made with your healthcare provider.


Aspect	Intravenous Immunoglobulin (IVIg)	Subcutaneous Immunoglobulin (SCIg)
Administration	Given directly into a vein.	Injected into the subcutaneous tissue under the skin.
Common Mild/Moderate Systemic Reactions	Common: headache, chills, fever, fatigue, nausea, muscle aches.	Infrequent: mild headaches, fatigue, dizziness, nausea.
Common Mild/Moderate Local Reactions	Infrequent: mild itching or irritation at the IV site.	Common: redness, swelling, pain, itching at the injection sites. Tends to diminish over time.
Infusion Speed Effect	Rapid infusion can increase the risk and severity of systemic reactions.	Often preferred for slower, more frequent dosing at home, which may help mitigate systemic reactions.
Risk of Severe Systemic Reactions	Rare but possible: anaphylaxis, aseptic meningitis, renal impairment, thrombosis.	Rare but possible: similar severe reactions, though less common.
Management	Often requires pre-medication and careful monitoring in a clinical setting.	Patients can learn to self-administer at home; management focuses on optimizing local site reactions.

Managing Side Effects and Boosting Well-being

Managing side effects is a proactive process that involves working closely with your doctor and making simple adjustments to your routine. Most reactions can be effectively managed with straightforward strategies.

Tips for managing side effects:

Hydrate adequately: Staying well-hydrated before, during, and after your infusion can help reduce headaches and other systemic side effects.
Discuss premedication: Your doctor may recommend taking over-the-counter medications such as acetaminophen or ibuprofen before your infusion to help prevent fever, headaches, and muscle aches.
Adjust infusion rate: If you experience reactions during the infusion, your nurse can slow the rate. A slower infusion rate is a proven method for reducing the severity of many side effects.
Get plenty of rest: Fatigue is a common reaction. Plan for extra rest and avoid strenuous activity in the day or two following your infusion.
Use warm/cold compresses: For local site reactions from SCIg, applying warm or cold compresses can help soothe the area.

When to Seek Immediate Medical Attention

While most immunoglobulin infusion side effects are mild, it is important to be aware of signs that may indicate a serious reaction. You should contact your healthcare provider immediately if you experience the following:

Severe headache, stiff neck, fever, or sensitivity to light (potential signs of aseptic meningitis).
Chest tightness, trouble breathing, or wheezing (signs of an allergic reaction or lung problem).
Severe nausea and vomiting.
Swelling, pain, or warmth in an arm or leg (potential blood clot).
Changes in urination, dark urine, or swelling in the face or limbs (signs of a kidney issue).
Signs of a stroke, such as sudden numbness or weakness on one side of the body, or trouble speaking.

Conclusion

For many patients, immunoglobulin infusions are a critical and effective therapy that improves their quality of life. Understanding how do you feel after an immunoglobulin infusion involves recognizing that while a range of side effects is common, most are manageable and temporary. Open and honest communication with your healthcare team is the best strategy for adjusting your treatment plan, managing discomfort, and ensuring the greatest possible benefit from your therapy. With the right preparation and post-infusion care, you can navigate the experience and focus on improving your health and well-being. More comprehensive details on specific side effects and management can be found through resources like the NIH.

Frequently Asked Questions

Yes, feeling fatigued or unusually tired is a very normal and common side effect after an immunoglobulin infusion. This can last for a day or two as your body processes the treatment.

The most common side effect reported for intravenous immunoglobulin (IVIg) is a headache. Many patients also experience flu-like symptoms such as chills, fever, and muscle aches.

To manage a headache after an IVIg infusion, you can stay well-hydrated and rest. If recommended by your doctor, over-the-counter pain relievers like acetaminophen or ibuprofen can also be helpful.

Most mild side effects, such as flu-like symptoms and fatigue, are temporary and resolve within 24 to 48 hours. Local site reactions from SCIg tend to improve as your body becomes accustomed to the therapy.

IVIg typically results in more systemic reactions like headaches, fever, and chills. SCIg side effects are most often localized to the injection site, causing redness, pain, and swelling, with fewer systemic issues.

You should contact your doctor if side effects are severe or persistent, such as a headache that won't go away or severe nausea. Seek immediate medical help for signs of a severe reaction like difficulty breathing, chest pain, or severe neck stiffness.

Yes, your healthcare provider may suggest taking pre-medications, such as acetaminophen or antihistamines, to minimize or prevent certain side effects before the infusion begins.