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What causes infusion reactions to rituximab?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on May 2, 2024.

Official answer


Rituximab infusion reactions are caused primarily by cytokine release in the body. Cytokines are immune system proteins in the body that help to fight infections but can cause an inflammatory response. Infusion reactions are a very common side effect of treatment with rituximab (Rituxan) and can occur in greater than 10% to 25% of patients across all approved uses for rituximab.

Although cytokines help fight infection, too many cytokines can be bad for the body. Sometimes these cytokine-related infusion-related reactions can be serious or lead to death. Be sure to tell your healthcare provider before you receive rituximab if you have ever had a severe reaction to Rituxan, rituximab or any rituximab product.

  • Your healthcare provider will monitor you for infusion side effects during treatment and is equipped to manage them should they occur.
  • Your healthcare provider will also give you medicines before your rituximab intravenous (IV) infusion to lower your chances of having a severe infusion-related reaction.
  • These medicines may include acetaminophen, antihistamines or corticosteroids.

How do I recognize an infusion reaction to rituximab?

Infusion reactions can occur while you are receiving the rituximab infusion or within one day after you receive your treatment with Rituxan.

Tell your healthcare provider or get medical help right away (for example, call 911) if you get any of these symptoms during or after an infusion of rituximab:

  • hives (red itchy welts) or rash
  • itching
  • swelling of your lips, tongue, throat or face
  • sudden cough
  • shortness of breath
  • difficulty breathing, or wheezing
  • weakness
  • dizziness
  • feel faint
  • palpitations (feels like your heart is racing or fluttering)
  • chest pain

Related: Review rituximab side effects (in more detail).

This is not all the information you need to know about rituximab (Rituxan) for safe and effective use and does not take the place of talking to your doctor about your treatment. Review the full rituximab information here, and discuss this information and any questions you have with your doctor or other health care provider.

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