Rituximab is a targeted therapy used for certain blood cancers and some autoimmune diseases. You receive it as an intravenous (IV) infusion in a clinic or hospital. Your care team often gives other medicines before the infusion to lower the chance of side effects. You will have regular labs and check-ins while on this medicine.
Brand Name(s)
- United States: Riabni; Rituxan; Ruxience; Truxima
- Canada: Riabni [DSC]; Rituxan; Riximyo; Ruxience; Truxima
Warning(s)
- Infusion reactions can happen during the infusion or within 24 hours. Tell your nurse right away if you have fever, chills, rash, itch, flushing, trouble breathing, chest tightness, dizziness, or swelling of the face, lips, or throat.
- Severe skin reactions (Stevens-Johnson syndrome/toxic epidermal necrolysis) are rare but serious. Get help right away for red, swollen, blistered, or peeling skin; sores in your mouth, nose, throat, or eyes; or red/irritated eyes.
- Hepatitis B reactivation can occur if you carry the virus or had it before. You will be tested before starting and watched during treatment and for months after. Report signs like yellow skin/eyes, dark urine, or stomach pain.
- Progressive multifocal leukoencephalopathy (PML) is a very rare brain infection that can be deadly. Report confusion, memory loss, changes in behavior, weakness on one side, trouble speaking, balance problems, or vision changes.
- Infection risk is higher. Wash hands, avoid people who are sick, and report fever, chills, cough, new sore throat, painful urination, or wounds that do not heal.
- Vaccines: Check with your doctor before any vaccines. Some may not work as well or may raise infection risk. Try to be up to date before treatment; avoid live vaccines during treatment and for a period after.
- Tumor lysis syndrome (TLS) can happen within 12 to 24 hours after the first treatment, especially with fast-growing cancers. Report fast or irregular heartbeat, confusion, muscle cramps/weakness, decreased urine, nausea, vomiting, or diarrhea.
- Allergies: Tell your team if you are allergic to rituximab or proteins from mice.
- Older adults (65+) may have a higher chance of side effects.
- Pregnancy and breastfeeding: Rituximab may harm an unborn baby. Use birth control during treatment and for 12 months after your last dose. Do not breastfeed during treatment or for 6 months after your last dose. A pregnancy test may be done before starting.
Kind of Cancers It Is Used For (not a complete list)
- Follicular lymphoma (CD20-positive)
- Diffuse large B-cell lymphoma (DLBCL)
- Mantle cell lymphoma (often with chemotherapy)
- Chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL)
- Marginal zone lymphoma (some cases)
Rituximab is also used for rheumatoid arthritis, granulomatosis with polyangiitis (GPA), microscopic polyangiitis, and pemphigus vulgaris. Your care team will confirm if this medicine is right for your condition.
Mechanism of Action
Rituximab is a monoclonal antibody that targets a protein called CD20 on B cells. When it attaches to CD20, it marks those B cells for removal by your immune system. This lowers the number of cancerous B cells and can slow or stop their growth. In autoimmune diseases, reducing B cells can calm an overactive immune response.
Common Side Effects
- During or soon after infusion: fever, chills, rash or itch, flushing, throat irritation, dizziness, or shortness of breath. Your team will monitor you and may slow or pause the infusion if needed.
- General: feeling tired or weak, headache, anxiety, trouble sleeping, night sweats.
- Stomach and mouth: nausea, vomiting, stomach pain, diarrhea, decreased appetite, and mouth irritation or sores (more common in cancer treatment).
- Muscles and joints: back pain, muscle or joint pain, muscle spasms.
- ENT and breathing: runny or stuffy nose, cough, sore throat.
- Skin: mild rash or flushing.
- Other: swelling in hands or feet, changes in blood pressure.
Most side effects are manageable. Call your care team right away for signs of an allergic reaction, infection, severe skin reaction, chest pain, trouble breathing, severe belly pain, confusion, severe dizziness or fainting, or any symptom that worries you.
Learn more about rituximab on MedlinePlus
Last Reviewed Date: 2025-12-04
Last reviewed: 2025-12-04
