Rituximab (Rituxan and MabThera) is a drug used to treat rheumatoid arthritis that has not improved with other types of medications, as well as certain forms of vasculitis. It works by turning off a part of the immune system that is not working properly in autoimmune diseases.
Rituximab is used in combination with methotrexate to treat rheumatoid arthritis that has not responded to one or more types of treatment, including TNF inhibitors. Rituximab also is used to treat certain types of vasculitis (an inflammatory condition affecting blood vessels), such as granulomatosis with polyangiitis or MPA. Occasionally rituximab is used to treat other immune problems, including lupus, and inflammatory muscle diseases when these are resistant to any other treatment. Rituximab also is used in the treatment of some blood disorders, including chronic lymphocytic leukemia and non-Hodgkin’s lymphoma.
Rituximab is given as an infusion into the vein (IV or “drip”). The infusion usually takes two - four hours, although occasionally it can take longer. A course of rituximab for rheumatoid arthritis usually consists of two 1000 mg doses given 15 days apart and often repeated within six months. To treat vasculitis, a smaller dose is given once a week for four weeks in a row. This is usually calculated based on your body surface area.
The effects of rituximab begin about six weeks after the infusions. Usually by the third month the full effect occurs, and can last up to nine months.
Sometimes, blood pressure can drop during the treatment. Those who take medications to lower their blood pressure may have to hold blood pressure medications before the infusions. This would need to be discussed with your doctor.
Mild side effects during or up to 24 hours after receiving rituximab may occur. These usually occur with the first infusion, and can include mild throat tightening, flu-like symptoms, rash, itchiness, dizziness, back pain, nausea, upset stomach, sweating, nervousness, muscle stiffness, and numbness. These symptoms can be reduced by receiving a steroid injection before the infusion, along with acetaminophen (Tylenol) and diphenhydramine (Benadryl). The infusion is sometimes stopped for a short while and then restarted at a slower rate if the symptoms get better. Rarely, patients will have more serious symptoms, such as wheezing, mouth or throat swelling, trouble breathing, or chest pain. Patients who experience these symptoms should tell their health care providers immediately; patients may receive stronger medications to treat those symptoms.
In the months after the treatment, some people may notice more frequent infections, such as colds or sinusitis. Usually, these are not severe. There are a few rare but serious side effects from rituximab. Patients who experience vision changes, loss of balance, difficulty walking, confusion, skin reactions, or mouth sores should contact their doctors immediately.
Combining treatment with other biologic drugs, which suppress the immune system, including etanercept (Enbrel), adalimumab (Humira), infliximab (Remicade), certolizumab (Cimzia), golimumab (Simponi), abatacept (Orencia), and tocilizumab (Actemra) may increase the risk of serious infections and is contra-indicated.
Tell your rheumatology provider if you have lung or heart problems, or have ever had any major infections (especially hepatitis). Let your health care providers know about all medications you are currently taking, including over-the-counter medications, supplements, and herbal therapies. Also, tell them about all allergic reactions you have had to medications. If you are a woman who can get pregnant, then discuss this with your provider before starting the medication. You may use reliable birth control before treatment and for 12 months afterward. Rituxan is considered safe in breastfeeding, and can be used in pregnancy for life-threatening cases. Vaccines are not as effective for several months after receiving rituximab, so you should receive necessary ones before starting treatment or between courses.
Updated December 2020 by Kanika Monga, MD, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.
This information is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.