Side Effects of Immunotherapy

What is Immune Therapy and what does it do?

Briefly, immunotherapy is a form of cancer treatment that enhances your own immune system or uses synthetic portions of the immune system to prevent breast cancer growth and recurrence. It utilizes a synthetic monoclonal antibody that is designed to bind only one kind of receptor.[1] The only available drug approved for treatment of breast cancer in the United States is trastuzumab, known by its trade name Herceptin.

Side Effects of Immunoherapy

Although immunotherapy is highly specific as to the kinds of cells it binds to, you may still suffer from a variety of side effects. Some of these occur within days to weeks of receiving the infusion, while others occur later. Furthermore, some side effects are minor and reversible and others are severe and permanent.

The most common side effects of this drug are flu-like symptoms, since it activates your own immune system, making your body think it is fighting an infection. These occur in approximately 40% of patients after their first infusion. They consist of the following symptoms:

  • Fever
  • Chills
  • Muscle  aches
  • Nausea

Other side effects that have been reported include:

  • Back, bone or joint pain
  • Generalized pain
    • Weakness
    • Rashes
    • Stomach ache
  • Vomiting
  • Diarrhea
  • Constipation
  • Headaches
  • Heartburn
  • Loss of appetite
  • Sleep disorders (insomnia)
  • Fatigue
  • Pale skin
  • Hot flushes
  • Numbness, burning or tingling in the extremities
  • Brittle nails
  • Acne
  • Nosebleeds
  • Depression

Immunotherapy can have more serious side effects, affecting your heart and lungs. According to research, cardiotoxicity occurs in 5-30% of patients receiving the drug, and this risk is elevated when given in conjunction with anthracycline chemotherapy.[2] Your doctor will monitor you closely to ensure that you are not experiencing these, sometimes requiring imaging studies of the heart or stress tests to do so.[3]

The complications associated with the lungs are more likely if the patient already has diseases of the lungs, such as emphysema, COPD or asthma. Also, if the cancer has metastasized to the lungs, the drug may cause further damage to them since it is fighting cancer directly in that area. Symptoms of this include:

  • Pulmonary edema – increased fluid inside the lung
  • Shortness of breath
  • Low blood pressure
    Pleural effusions  – increased fluid around the lungs

Your doctor will monitor closely for these side effects as well, both with physical exam and possible chest x-rays.

How to Manage the Potential Side Effects

The following is a list of side effects and methods to alleviate them:

Side Effect

Alternative Method to Manage

Traditional Method to Manage



General precautions

Eat a well-balanced, healthy diet during your treatment. Drink lots of water. Get plenty of rest. Avoid alcohol.
Nausea Eat several small meals a day vs. a few large meals

Try drinking ginger or peppermint tea

Anti-nausea medication
Drowsiness avoid driving
Fever Take acetaminophen or ibuprofen
General Flu-like symptoms Try to stay warm with blankets or a warm bath

Drink plenty of fluids

Take acetaminophen or ibuprofen
Headache Take acetaminophen or ibuprofen
Dizziness avoid driving
Aches and Pains Take acetaminophen or ibuprofen


All drugs have side effects associated with them. Immunotherapy drugs are no exception but many of them are preventable or manageable. If you feel like you are experiencing any of the side effects above, see your doctor immediately.


1 Hudis, CA (2007). Trastuzumab–Mechanism of Action and use in Clinical Practice. N England J Medicine, 357 (1): 39–51

2 Sarg, M. S. and Gross, A. D. (2007). The Cancer Dictionary Third Edition. New York: Checkmark Books.

3 McKeage, K; and Lyseng-Williamson, KA (2008). Trastuzumab: A Pharmacoeconomic Review of its Use in Early Breast Cancer. PharmacoEconomics, 26(8):699-719.

This article was originally published on July 27,2012 and last revision and update of it was 9/2/2015.