Adverse Reactions to Chemotherapy and Other Cancer Drugs

What are adverse reactions to drugs? 
Sometimes, patients can develop symptoms or feel sick from a drug they are taking. When this happens, patients may be diagnosed as having an adverse drug reaction. There are many different types and causes of adverse drug reactions. 

One type of adverse drug reaction is a side effect. Side effects are fairly common and can occur in anyone taking enough doses of a drug for a long enough period. Side effects are usually predictable. Examples of side effects can include being sleepy after taking certain antihistamines, developing a stomach ulcer after taking aspirin, developing diarrhea after taking an antibiotic and losing your hair after receiving chemotherapy. 

Another type of adverse drug reaction is a hypersensitivity reaction. These reactions are less common than side effects and are unpredictable. For most hypersensitivity reactions, it is unclear why only certain people will develop them. Examples of hypersensitivity reactions can include a rash after taking an antibiotic, hives after taking a pain medication, trouble breathing and dizziness during an infusion of a chemotherapy drug. 

Are cancer drugs associated with hypersensitivity reactions? 
Yes. Many cancer drugs have been associated with hypersensitivity reactions. Some examples include chemotherapy agents (e.g. carboplatin, oxaliplatin, docetaxel, paclitaxel), biologics (e.g. rituximab, cetuximab) and immune checkpoint inhibitors (e.g. avelumab, nivolumab). 

How do I know if I am having a hypersensitivity reaction? 
Symptoms of a hypersensitivity reaction can involve many parts of the body, and not every person will experience the same kind of symptoms. You may become itchy, notice a rash, develop swelling, have trouble breathing, feel like you want to vomit or feel faint. Other symptoms can include pain, fevers, chills or shaking. Some symptoms happen quickly after taking a medication while other symptoms take days to develop. If you develop any of these symptoms, tell your care team right away. 

What is anaphylaxis? 
Anaphylaxis is a type of hypersensitivity reaction that is severe and can occur quickly after taking a drug. Symptoms of anaphylaxis typically involve the skin (hives, swelling), the lungs (trouble breathing, wheezing, low oxygen levels), the heart (low blood pressure, dizziness) and the stomach (nausea, vomiting, diarrhea). 

What will happen if I tell my care team that I think I am having a reaction? 
After you tell someone on your care team that you do not feel well, your temperature, heart rate, blood pressure and breathing will be checked. Someone on your care team will also look at your skin for rashes, check for any swelling and listen to your heart and lungs. Then, you will receive medications that treat your specific symptoms. 

How are hypersensitivity reactions treated? 
Treatment of a hypersensitivity reaction largely depends on what symptoms you have. Antihistamines such as diphenhydramine and cetirizine may be used to treat itching, hives and rash. Other medications that may be used include steroids, anti-nausea medications and acetaminophen. 

How is anaphylaxis treated? 
Epinephrine is the main treatment of anaphylaxis. This drug is usually given as a shot in your thigh. Depending on what other symptoms you are having, you may also receive oxygen, an inhaler, intravenous (IV) fluids and any of the medications listed above. 

How long will I stay after I have a hypersensitivity reaction? 
It depends on the type and severity of the reaction. You may need to be monitored for at least a few hours after your reaction so that nurses and doctors can make sure your symptoms do not come back. If your reaction is more serious and your care team is concerned, you might need to go to the emergency department or stay overnight in the hospital. 

I developed anaphylaxis to my chemotherapy medication. Does this mean I cannot receive it again? 
Not necessarily. You will need to speak with your provider about your medical condition and what other drugs may be appropriate for treating it. There may be another type of medication that you can take. Sometimes, however, there is no other option than the drug that caused anaphylaxis. In these cases, an allergist / immunologist might be able to help. 

What is desensitization? 
Desensitization is a special procedure that an allergist / immunologist can perform to help patients who have developed anaphylaxis to a drug to continue receiving the same drug in a closely monitored way. Desensitization to a particular drug involves slowly infusing the drug over several hours by gradually increasing the dose of the medication. While generally considered safe, some patients can still develop symptoms during desensitizations. Most of the time, these symptoms are mild. Desensitizations are usually performed in the hospital or an infusion center while you are under the care of an allergist / immunologist and your oncologist. However, not all hospitals or infusions centers are able to perform them. 

How do I find an allergist to talk to?
Use our Find an Allergist / Immunologist tool to locate an allergist / immunologist close to you. 

Find out more about drug allergies. 

References
1. Shaker MS, Wallace DV, Golden DBK, Oppenheimer J, Bernstein JA, Campbell RL, et al. Anaphylaxis-a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis. J Allergy Clin Immunol 2020; 145:1082-123. 
2. Khan DA, Banerji A, Blumenthal KG, Phillips EJ, Solensky R, White AA, et al. Drug allergy: A 2022 practice parameter update. J Allergy Clin Immunol 2022; 150:1333-93. 
3. Golden DBK, Wang J, Waserman S, Akin C, Campbell RL, Ellis AK, et al. Anaphylaxis: A 2023 practice parameter update. Ann Allergy Asthma Immunol 2024; 132:124-76. 
4. Barroso A, Estevinho F, Hespanhol V, Teixeira E, Ramalho-Carvalho J, Araujo A. Management of infusion-related reactions in cancer therapy: strategies and challenges. ESMO Open 2024; 9:102922. 
5. Chow TG, Franzblau LE, Khan DA. Adverse Reactions to Biologic Medications Used in Allergy and Immunology Diseases. Curr Allergy Asthma Rep 2022; 22:195-207. 
6. Castells MC, Tennant NM, Sloane DE, Hsu FI, Barrett NA, Hong DI, et al. Hypersensitivity reactions to chemotherapy: outcomes and safety of rapid desensitization in 413 cases. J Allergy Clin Immunol 2008; 122:574-80. 


12/2/2025