Rituxan (rituximab)

Reviewed by: HU Medical Review Board | Last reviewed: March 2022 | Last updated: April 2022

Rituxan (Rituximab) is an engineered biologic medication that is approved for use against rheumatoid arthritis, in combination with methotrexate. Methotrexate is the most commonly prescribed medicine against RA. It is known as a disease-modifying anti-rheumatic drug (DMARD).1

When given with methotrexate, Rituxan reduces the signs and symptoms of RA and slows the structural damage that occurs in adults with moderately- to severely-active disease, resulting in improved physical functioning and increased quality of life.2

Rituxan is recommended as a second-line defense against RA for people who do not respond to another class of medications (called TNF inhibitors).3

Rituxan is also used to treat other diseases, including non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, and granulomatosis with polyangiitis (a rare disease that involves inflammation of blood vessels and affects the lungs, kidneys, and sinuses).3

What are the ingredients in Rituxan?

The active ingredient in Rituxan is rituximab.3

How does Rituxan work?

Rituxan is one of several monoclonal antibodies used to treat RA. Our bodies naturally produce antibodies, which are immune factors that act against bacteria, viruses, and other foreign organisms that invade and pose a threat to our health. Drug makers have engineered a variety of antibodies to target the mechanisms that cause certain diseases, including RA.

Rituxan is an antibody that targets the protein CD20 that occurs on the surface of B-cells, which play a key role in immune response. When Rituxan binds to CD20, it triggers the destruction of the cells it attaches to. Reducing the number of mature B-cells limits their ability to promote the inflammation and joint damage that is a hallmark of RA.3

What are the possible side effects of Rituxan?

Common side effects with Rituxan include:3,4,5

  • Infections
  • Body aches
  • Tiredness
  • Nausea
  • Upper respiratory tract infections, including colds and sinus problems
  • Infusion-related reactions, including:
    • Flu-like symptoms
    • Headache
    • Shortness of breath
    • Low blood pressure
    • Fever and chills
    • Stomach symptoms
    • Skin rash
    • Allergy

In some patients, Rituxan can cause more harmful side effects. Patients who take Rituxan are at increased risk for serious infections, including viral infections, bacterial infections, reactivation of hepatitis B, and fungal infections.

Some people have had serious infusion reactions as much as 24 hours after treatment. Other rare but serious side effects include severe sores and ulcers in the mouth or skin, serious viral infections of the brain, tumor lysis syndrome, heart problems, kidney problems, and stomach or bowel problems.3,5

This is not an exhaustive list of all potential side effects of Rituxan. If you notice any new or worsening side effects, contact your doctor or healthcare provider immediately.For more information on adverse effects, see the FDA black box warning for Rituxan.

Things to note about Rituxan

Before taking Rituxan, tell your doctor if you3,5:

  • Have a current infection or are prone to recurring infections, including open cuts
  • Have a weakened immune system
  • Have or have had Hepatitis B
  • Have or have had an irregular heartbeat, heart disease, or heart failure
  • Have or have had other medical conditions, including kidney disease
  • Are scheduled to receive a vaccine
  • Are pregnant or plan to become pregnant or are breastfeeding

There is an increased risk of serious infections with Rituxan. This is because Rituxan can decrease the ability of the immune system to fight infections. Rituxan should not be taken by a patient with an active infection and should be stopped until the infection is resolved. There is also a risk of reactivation of hepatitis B virus (HBV) infection and with Rituxan. Carriers of the virus should be monitored while taking the medication and for several months after treatment.3,5

Patients at risk for irregular heart rhythms, chest pain, or heart disease should be monitored carefully during treatment with Rituxan. Patients taking Rituxan should not take live vaccines. It can also harm a developing fetus, so pregnant women should not take this medication.3,5

Tell your doctor about any medications or supplements you are taking while on Rituxan, because it doesn’t mix well with certain medicines, especially certain chemotherapy agents. It is important for doctors to test you for Hepatitis B before you take Rituxan.3,5

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