An infusion reaction is an adverse event that can occur when a substance is given directly into a vein via an intravenous (IV) infusion. These reactions are the body’s response to the infused medication or solution. While some are mild and resolve on their own, others can be severe and require immediate medical attention.
Understanding Infusion Reactions
Infusion reactions occur when the body’s immune system or other physiological systems respond to substances introduced into the bloodstream. The National Cancer Institute classifies these reactions by severity, from mild to potentially life-threatening.
Reactions are broadly categorized as immune-mediated (allergic) or non-immune-mediated (non-allergic). Immune-mediated reactions often involve the immune system’s targeted response, sometimes after previous exposure. Non-immune-mediated reactions do not involve an immune response but result from direct pharmacological effects or the release of proteins like cytokines.
Recognizing the Signs
Infusion reactions manifest through various symptoms affecting different body systems. Skin reactions are common, including itching, redness or flushing on the face and neck, rash, or hives.
Respiratory symptoms may include shortness of breath, coughing, wheezing, or chest discomfort. Gastrointestinal symptoms such as nausea, vomiting, diarrhea, or abdominal pain can also occur. Cardiovascular changes, like a fast heartbeat, changes in blood pressure (low or high), or dizziness, are also possible.
Infusion reactions can occur immediately, within minutes to hours after the infusion begins, or they can be delayed, appearing days or even weeks later. Immediate reactions often present with symptoms like flushing, itching, or shortness of breath. Delayed reactions may involve symptoms such as rash, muscle pain, or fatigue.
Causes and Contributing Factors
Infusion reactions stem from various underlying reasons. Allergic reactions, a type of immune-mediated response, can involve immunoglobulin E (IgE) antibodies. These reactions occur after a person has been sensitized to the drug, making them more likely during subsequent infusions rather than the first.
Non-allergic reactions, such as cytokine release syndrome, do not involve an immune response. Instead, they are caused by the direct pharmacological effects of the drug or the release of cytokines, proteins that can cause inflammation. These reactions often appear during the first infusion.
Factors related to the infused substance itself, like the specific medication, its concentration, or the infusion rate, can influence the likelihood of a reaction. Patient-specific factors, such as a history of allergies, previous infusion reactions, or underlying medical conditions, also increase the risk. Certain cancer treatments, including some taxane chemotherapies, platinum compounds, and monoclonal antibodies, have a higher risk of causing infusion reactions.
Management and Prevention
When an infusion reaction occurs, immediate actions are taken to ensure patient safety. Healthcare providers pause or stop the infusion, assess the patient’s breathing, temperature, blood pressure, and heart rate, and administer supportive care. Medications like antihistamines (e.g., diphenhydramine), corticosteroids (e.g., dexamethasone), or acetaminophen may be given to alleviate symptoms. For severe reactions, particularly anaphylaxis, epinephrine is administered.
Prevention strategies are often employed. Pre-medication is a common approach, where patients receive medications like antihistamines, corticosteroids, or anti-fever medicines before the infusion to reduce the likelihood or severity of a reaction. Administering the infused medication at a slower rate can also help. Careful patient monitoring throughout the infusion process is performed to detect early signs of a reaction. If a reaction has occurred, a desensitization protocol might be used, which involves gradually increasing the dose of the medication to help the body tolerate it.