Rituximab

What is rituximab?

Rituximab (also called Rituxin^®) is a medicine used to treat certain types of cancer and autoimmune diseases, including immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA). Your doctor will explain why it is being used for you. It is a colorless liquid given into a vein (IV) over a period of time, usually several hours.

Rituximab is a type of medicine called a monoclonal antibody. It works by attacking immune cells in the body called B-cells. B-cells make antibodies, which are the proteins that destroy platelets in ITP and destroy red blood cells in AIHA. By damaging B-cells, fewer platelets and red blood cells will be destroyed.

Possible side effects of rituximab

Early

• Flu-like reaction, which may cause fever, chills, headache, shortness of breath, and dizziness
• Decreased blood pressure
• Nausea or vomiting
• Joint or muscle pain

Later (more than a day after treatment starts)

• Low blood counts, which can increase the chance of getting an infection
• Diarrhea
• Rash
• In the treatment of cancer: Tumor lysis syndrome (tumor breakdown causing changes in electrolytes)
• Decreased kidney function
• Decreased liver function
• Hepatitis B virus (HBV) reactivation

If you have any of these side effects, tell the doctor right away:

• Sudden and severe pain in the upper stomach with nausea, vomiting, or loss of appetite
• Decrease in how much or how often you urinate
• An allergic reaction, including itching, skin redness, severe chills, shortness of breath, low blood pressure, or pain in the chest, side, or back

These are the most common side effects, but there may be others. Please report all side effects to the doctor or nurse.

In case of a severe side effect or reaction, call the doctor, nurse, or pharmacist at 901-595-3300. If you are outside the Memphis area, dial toll-free 1-866-2STJUDE (1-866-278-5833), and press 0 once the call is connected.

Special instructions for rituximab

• You may be asked to not take blood pressure medicines 24 hours before and after your infusion of rituximab. It is important to follow the instructions from your doctor.
• The nurse will observe you closely during and after the infusion of rituximab because some people have a severe reaction to this drug. Your vital signs will be taken often during the infusion.
• Tell your nurse how you are feeling during the rituximab infusion. Let the nurse know if you are feeling short of breath, have chills, feel lightheaded or dizzy, or feel like your muscles are stiffening. There are medicines that can be given to lessen or prevent these effects.
• The doctor may ask you to take diphenhydramine (Benadryl^®) and acetaminophen (Tylenol^®) before rituximab is given to prevent the flu-like side effects that can occur.
• The staff will take blood samples regularly to check for changes in liver function and blood counts.
• It may be easier for you to get infections while you are receiving rituximab. Stay away from crowds or people with colds, flu, or other infections. If you get a fever, you should call your doctor or nurse.
• Rituximab can cause nausea and vomiting. The doctor may prescribe medicine to keep you from feeling sick and throwing up after you receive rituximab.
• It is not known whether rituximab passes into breast milk. This medicine might cause serious harm to a nursing infant. Women who are taking rituximab should not breast-feed a baby.
• Talk to the doctor or pharmacist about when your child should receive vaccinations after rituximab therapy. 

Pregnancy risk for rituximab

This medicine may be harmful to an unborn child. Avoid becoming pregnant during treatment. Contact one of your caregivers at St. Jude if you are sexually active or think you may be pregnant.