Intravenous Immunoglobulin (IVIg) is a medical treatment that provides a concentrated supply of antibodies, which are proteins collected from the plasma of thousands of healthy blood donors. This therapy is administered directly into a vein to help boost a weakened immune system or modulate an overactive one, treating a range of immunodeficiency disorders and autoimmune conditions. It is common to experience certain temporary physical reactions immediately following the procedure. Understanding the difference between expected reactions and signs of a serious problem is important for managing your recovery.
Immediate and Common Post-Infusion Reactions
The majority of reactions experienced after an IVIg infusion are mild and are often related to the rate at which the fluid was delivered. These common adverse effects typically occur during the infusion or within the first 24 hours afterward. Fewer than five percent of people experience moderate or severe side effects.
Post-infusion headache is one of the most frequently reported side effects, sometimes presenting with a delayed onset between six and twelve hours after the infusion ends. This headache can sometimes persist for 24 to 72 hours. Other flu-like symptoms are also common, including a low-grade fever, chills, and a feeling of general discomfort or malaise. These symptoms represent the body’s transient response to the influx of new antibodies.
Mild nausea, muscle aches (myalgia), or back pain may also occur. Less frequently, patients may notice localized reactions at the infusion site, such as mild redness, tenderness, or swelling. These responses often lessen with subsequent infusions as the body adjusts to the treatment. For many people, the symptoms will be most pronounced after the very first treatment session.
Post-Infusion Care and Recovery Timeline
Managing the immediate post-infusion period involves proper hydration, which is a fundamental component of post-infusion care. Hydration helps the body process the large protein load and volume of fluid, reducing the risk of headaches and minimizing strain on the kidneys. Many providers recommend consuming at least eight cups of fluid, such as water or electrolyte drinks, starting one to two days before the infusion and continuing for one to two days after the procedure.
For managing the common headache or mild fever, over-the-counter medications like acetaminophen or ibuprofen may be used, but only after consultation with your physician. These medications are often used as premedication before the infusion begins to help prevent symptoms from developing. If flu-like symptoms like chills or muscle aches occur, resting and maintaining warmth can help alleviate the temporary discomfort.
It is generally recommended to avoid strenuous activity for 24 to 48 hours following the infusion to allow the body to recover. While common side effects like headaches and malaise typically resolve within three days, the therapeutic benefits of the IVIg may take longer to become noticeable. For many patients, the full effects of the treatment may begin to be recognized several weeks after the initial infusion.
Recognizing Serious Adverse Effects
It is important to be aware of rare, serious adverse events that require immediate medical attention. These reactions can sometimes occur hours or even a few days after the infusion is complete.
A severe, persistent headache accompanied by a stiff neck and extreme sensitivity to light (photophobia) could be a sign of aseptic meningitis, which is a rare but known complication. Other signs requiring immediate medical intervention relate to potential thrombotic events, or blood clots, which may present as chest pain, shortness of breath, or swelling and pain in one leg. Symptoms of acute kidney injury, such as a significant decrease in urine output, swelling in the lower extremities, or dark-colored urine, also warrant urgent medical evaluation.
Anaphylaxis, a life-threatening allergic reaction, is extremely rare. Signs include difficulty breathing, wheezing, swelling of the throat or face, or a sudden drop in blood pressure. If you experience any severe or alarming symptoms, you must stop all activity and contact emergency medical services right away.