Rituximab
Pronunciation: ri-TUCK-si-mab.
- Generic name
- rituximab
- Brand names
- Rituxan (United States, Canada), MabThera (United Kingdom, European Union, Australia, New Zealand), Truxima, Ruxience, Riximyo, Rixathon, Blitzima (approved biosimilars, multiple markets)
- Drug class
- CD20-directed cytolytic monoclonal antibody (biologic)
- Form
- Concentrate for solution for infusion, or solution for subcutaneous injection
- Route
- Intravenous infusion (and subcutaneous injection for some formulations/indications)
- Legal status
- Prescription-only medicine, administered under specialist medical supervision with resuscitation facilities available
Availability and supply rules vary by country
Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand
Australia: MabThera (5) · Full directory
Boxed warning: Rituximab carries four serious, potentially fatal risks
FATAL INFUSION REACTIONS: Fatal infusion-related reactions can occur within 24 hours of a rituximab infusion; about 80% of fatal reactions have occurred with the first infusion. SEVERE MUCOCUTANEOUS REACTIONS: Severe skin and mucous membrane reactions, some fatal, including Stevens-Johnson syndrome and toxic epidermal necrolysis, have occurred. HEPATITIS B VIRUS (HBV) REACTIVATION: HBV reactivation can occur, in some cases resulting in fulminant hepatitis, liver failure, and death; all patients must be screened for HBV infection before starting treatment. PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY (PML): PML, a rare but serious brain infection, can occur and has resulted in death. (1)
What rituximab is and how it works
Rituximab is a biologic medicine (a monoclonal antibody) given by infusion into a vein (or, for some products, by injection under the skin), that targets and helps destroy a type of white blood cell called a CD20-positive B-lymphocyte. It is used for certain blood cancers and certain serious autoimmune and inflammatory conditions. (1)
Rituximab is a powerful medicine that is always given by a specialist team in a setting equipped to manage serious reactions. It carries four possible, potentially fatal risks -- severe infusion reactions, severe skin/mucous-membrane reactions, reactivation of hepatitis B, and a rare brain infection called PML -- which is why you will be closely monitored before, during, and after each infusion, and screened for hepatitis B before you start.
Mechanism of action: how rituximab works
Rituximab is a chimeric monoclonal antibody that binds the CD20 antigen on the surface of B-lymphocytes, triggering cell-death mechanisms (complement-dependent cytotoxicity, antibody-dependent cellular cytotoxicity, and apoptosis) that deplete CD20-positive B-cells, including malignant B-cells in certain lymphomas/leukaemias and pathogenic B-cells in certain autoimmune conditions. (1)
What rituximab is used for
Non-Hodgkin's lymphoma (NHL)
Used alone or with chemotherapy for certain CD20-positive B-cell non-Hodgkin lymphomas, including relapsed/refractory low-grade or follicular disease and, in combination with chemotherapy, previously untreated follicular or diffuse large B-cell lymphoma. Also used in children 6 months and older with certain advanced-stage CD20-positive lymphomas/leukaemias, in combination with chemotherapy. (1)
Chronic lymphocytic leukaemia (CLL)
Used in combination with fludarabine and cyclophosphamide for chronic lymphocytic leukaemia. (1)
Rheumatoid arthritis (RA)
Used in combination with methotrexate in adults with moderately to severely active rheumatoid arthritis who have not responded adequately to one or more TNF-antagonist medicines. (1)
Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA)
Used in combination with glucocorticoids in adults and children 2 years and older with these forms of ANCA-associated vasculitis. (1)
Pemphigus vulgaris (PV)
Used for moderate to severe pemphigus vulgaris in adults, alongside a tapering course of glucocorticoids. (1)
Before taking rituximab
Do not take / not appropriate for
- There are no absolute contraindications listed on the current US label, but rituximab must not be given if you have had a severe or life-threatening allergic (anaphylactic) reaction to rituximab or any component of the product -- discuss any prior reaction with your specialist team. (all patients) (1)
Tell your clinician about
- Whether you have ever had hepatitis B, hepatitis C, or are a carrier of hepatitis B -- you will be screened for hepatitis B (HBsAg and anti-HBc) before treatment starts.
- Any history of heart disease, including arrhythmias.
- Any history of severe infections, or a weakened immune system.
- Whether you have a high number of circulating malignant (cancer) cells, which raises the risk of tumour lysis syndrome.
- Whether you are, or could become, pregnant, or are breastfeeding.
- Any recent or planned vaccinations, especially live vaccines.
- Every other medicine you take.
How to take rituximab
- Rituximab is given only by a specialist healthcare team, in a setting with full resuscitation facilities available, because of the risk of severe infusion reactions.
- You will usually be given other medicines (premedication), such as an antihistamine and paracetamol/acetaminophen, and sometimes a corticosteroid, before each infusion to help reduce the risk and severity of infusion reactions.
- Your infusion rate will typically start slowly and may be increased gradually if you tolerate it well; your care team will decide the exact schedule and rate for your condition.
- You will be screened for hepatitis B before your first dose.
- The number and spacing of infusions depends on your specific condition and how you respond -- this is entirely decided and managed by your specialist team.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)
Missed dose
Rituximab is given on a schedule set and managed by your specialist team. If you are unable to attend a scheduled infusion, contact your treatment centre as soon as possible to arrange a new appointment; do not attempt to adjust your own schedule.
Overdose
Because rituximab is given under direct medical supervision, an accidental overdose would be identified and managed immediately by your treatment team. There is no specific antidote; management is supportive and directed by your care team, with immediate access to emergency treatment for infusion reactions. (1)
Side effects
Reactions during or shortly after an infusion are common and are closely monitored for by your care team. Some effects -- on the skin, liver, nervous system, heart, and immune system -- are rare but serious and are the reason for the boxed warning and close monitoring described above.
Infusion-related symptoms (fever, chills, nausea, headache, itching, flushing)
What to notice: Very commonly reported, usually during or shortly after an infusion, and usually managed by your care team by slowing or briefly pausing the infusion.
What to do: Tell your infusion team immediately about any new symptom during or after your infusion -- they are specifically monitoring for this. (1) (2)
Low blood cell counts (e.g. low white blood cells)
What to notice: Commonly identified through routine blood tests, increasing infection risk.
What to do: Attend all scheduled blood tests; tell your team about fever, sore throat, or other signs of infection. (1)
Fatigue, upper respiratory infection symptoms, or urinary tract infection symptoms
What to notice: Commonly reported, varying by the condition being treated.
What to do: Tell your care team if these are severe or persistent. (1)
Signs of a severe infusion reaction
What to notice: Difficulty breathing, wheezing, swelling of the face or throat, chest pain, sudden severe dizziness, or a sudden drop in blood pressure -- most often during or within 24 hours of an infusion.
What to do: This is a medical emergency during a monitored infusion -- your care team is trained to manage it immediately; if it develops after you have left the infusion centre, seek emergency care right away. (1)
Severe skin or mouth reaction (possible Stevens-Johnson syndrome or toxic epidermal necrolysis)
What to notice: Blistering or peeling skin, painful sores in the mouth, eyes, or genitals, or a widespread rash, sometimes with fever.
What to do: Seek emergency medical help immediately -- this is a rare but potentially fatal reaction described in the boxed warning. (1)
Possible hepatitis B reactivation
What to notice: Unusual tiredness, loss of appetite, yellowing of the skin or eyes, dark urine, or abdominal pain.
What to do: Contact your care team promptly; this is why hepatitis B screening is required before treatment and monitoring may continue during and after treatment. (1)
Possible progressive multifocal leukoencephalopathy (PML)
What to notice: New or worsening confusion, vision problems, weakness on one side of the body, difficulty speaking, or changes in coordination or balance developing over days to weeks.
What to do: Seek prompt medical attention -- PML is a rare but serious brain infection described in the boxed warning and needs urgent evaluation. (1)
Signs of tumour lysis syndrome
What to notice: Usually detected through blood tests soon after an infusion in people with a high number of circulating cancer cells; may include muscle cramps, weakness, or reduced urination.
What to do: This is monitored for and managed by your care team, especially after the first infusion in higher-risk patients. (1) (2)
Irregular heartbeat
What to notice: Palpitations, chest discomfort, or feeling faint.
What to do: Tell your care team promptly, especially if you have existing heart disease. (2)
Signs of bowel obstruction or perforation
What to notice: Severe abdominal pain, distension, vomiting, or inability to pass stool or gas.
What to do: Seek emergency medical help immediately. (1)
Serious warnings
Fatal infusion-related reactions — boxed_warning
Symptoms: Difficulty breathing, wheezing, facial or throat swelling, chest pain, or sudden drop in blood pressure, most often during or within 24 hours of an infusion (about 80% of fatal reactions occurred with the first infusion).
Action: Rituximab is given only in a setting equipped with resuscitation facilities; premedication and close monitoring are used to reduce this risk, and the infusion is stopped immediately by the care team if a severe reaction occurs. (1)
Severe mucocutaneous reactions (including Stevens-Johnson syndrome and toxic epidermal necrolysis) — boxed_warning
Symptoms: Blistering or peeling skin, painful mouth/eye/genital sores, or a widespread rash, sometimes with fever.
Action: Seek emergency medical help immediately; some cases have been fatal. (1)
Hepatitis B virus (HBV) reactivation — boxed_warning
Symptoms: Unusual tiredness, loss of appetite, yellowing of skin/eyes, dark urine, or abdominal pain -- may occur even in people who previously had inactive/resolved hepatitis B.
Action: All patients are screened for HBV (HBsAg and anti-HBc) before starting treatment; some fatal cases of fulminant hepatitis and liver failure have occurred. (1)
Progressive multifocal leukoencephalopathy (PML) — boxed_warning
Symptoms: New or worsening confusion, vision problems, weakness on one side of the body, difficulty speaking, or coordination/balance changes developing over days to weeks.
Action: Seek prompt medical attention; PML is a rare, serious brain infection that has resulted in death. (1)
Tumour lysis syndrome — high caution
Symptoms: Usually detected through blood tests; can include muscle cramps, weakness, or reduced urination, most often after the first infusion in patients with a high number of circulating malignant cells.
Action: Your care team may give preventive hydration and medicines before your first infusion if you are at higher risk. (2)
Serious infections — high caution
Symptoms: Fever, chills, cough, or other signs of bacterial, fungal, or viral infection.
Action: Tell your care team promptly about any possible infection; rituximab can weaken the immune system's ability to fight infection. (1)
Cardiac arrhythmias — high caution
Symptoms: Palpitations, chest discomfort, or feeling faint.
Action: Tell your care team if you have existing heart disease before starting treatment; report new heart symptoms promptly. (2)
Bowel obstruction and perforation — emergency
Symptoms: Severe abdominal pain, distension, vomiting, or inability to pass stool or gas.
Action: Seek emergency medical help immediately. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Live vaccines | Live vaccines are not recommended during and for a period after rituximab treatment, since the immune response needed for the vaccine to work safely may be impaired. | Tell your care team about any vaccination plans before, during, and after treatment. (1) |
| Other immunosuppressive or biologic medicines | Combined use may further increase infection risk. | Tell your care team about every other medicine you take, including other treatments for rheumatoid arthritis or autoimmune disease. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
People who can become pregnant
Use effective contraception during treatment and for 12 months after your last dose, as advised by your care team. Tell your care team immediately if you become pregnant or suspect you might be. (1)
Breastfeeding
Breastfeeding is not recommended during treatment (and, per UK guidance, for around 6 months afterward) because of the potential for effects on a nursing infant. (1) (2)
People with a history of hepatitis B
You will be screened for hepatitis B before treatment starts. If you have current or past hepatitis B infection, your care team will discuss monitoring and, if needed, preventive antiviral treatment. (1)
Children
Rituximab is used in children for specific indications (certain lymphomas from 6 months of age; granulomatosis with polyangiitis/microscopic polyangiitis from 2 years of age), always under specialist paediatric care. (1)
Monitoring
Before starting
- Hepatitis B screening (HBsAg and anti-HBc) for all patients.
- Assessment of cardiovascular history and, for higher tumour-burden patients, tumour lysis syndrome risk.
- Full blood count and other baseline blood tests as directed by your specialist team.
- Pregnancy status review for anyone who can become pregnant.
During treatment
- Continuous monitoring during and immediately after each infusion for signs of an infusion reaction.
- Periodic blood counts and liver function monitoring.
- Ongoing awareness of new neurological symptoms that could suggest PML.
- Ongoing hepatitis B monitoring for at-risk patients.
- Cardiac monitoring for patients with pre-existing heart disease.
Storage
Store refrigerated at 2C to 8C (36F to 46F), protected from direct light, in the original carton until use; do not freeze. Prepared infusion solutions are handled and stored by clinical staff per local pharmacy protocols.
Professional information
Clinician-facing context only. Use the current local product information in full, including the applicable premedication, infusion-rate escalation, and monitoring protocols for the specific indication and product (originator or biosimilar) being used.
United States
Indication: Varies by indication (NHL, CLL, RA, GPA/MPA, PV) -- see full prescribing information for the specific weight/BSA-based regimen, premedication, and infusion-rate schedule for each indication.
Dose summary: Individualised, indication-specific IV infusion regimens (e.g. 375 mg/m^2 weekly for certain NHL regimens; fixed 1000 mg IV infusions two weeks apart for RA), always with premedication and gradual infusion-rate escalation per label.
Renal context: Not extensively characterised in the sources reviewed; use current local product information. (1)
Hepatic guidance
Screen for HBV before initiation; monitor patients with current or prior HBV infection for clinical and laboratory signs of hepatitis during and for several months after therapy, per current local guidance.
Overdose note
No formal overdose data; manage supportively with immediate access to resuscitation facilities given the infusion-reaction risk, per local toxicology and oncology/rheumatology guidance. (1)
Frequently asked questions
Does rituximab have a boxed warning?
Yes. The current US prescribing information carries a four-part boxed warning covering fatal infusion-related reactions, severe mucocutaneous reactions (including Stevens-Johnson syndrome and toxic epidermal necrolysis), hepatitis B virus reactivation, and progressive multifocal leukoencephalopathy (PML), a rare but serious brain infection. (1)
Why do I need a hepatitis B test before starting rituximab?
Rituximab can cause hepatitis B to reactivate, even in people whose infection was previously inactive or resolved, sometimes leading to serious or fatal liver damage. All patients are screened for hepatitis B (HBsAg and anti-HBc) before treatment begins. (1)
Why is rituximab given so slowly, and why do I need other medicines beforehand?
Rituximab infusions can trigger serious reactions, most often with the first dose. Premedication (such as an antihistamine, paracetamol/acetaminophen, and sometimes a corticosteroid) and a gradual infusion rate, with close monitoring throughout, are used to reduce this risk. (1) (2)
What is the mechanism of action of rituximab?
Rituximab is a chimeric monoclonal antibody that binds the CD20 antigen on the surface of B-lymphocytes, triggering cell-death mechanisms (complement-dependent cytotoxicity, antibody-dependent cellular cytotoxicity, and apoptosis) that deplete CD20-positive B-cells, including malignant B-cells in certain lymphomas/leukaemias and pathogenic B-cells in certain autoimmune conditions. (1)
What is the generic name of Rituximab?
The generic name is rituximab. It is sold under brand names including Rituxan (United States, Canada), MabThera (United Kingdom, European Union, Australia, New Zealand), Truxima, Ruxience, Riximyo, Rixathon, Blitzima (approved biosimilars, multiple markets). (1) (2)
References
- RITUXAN (rituximab) injection, for intravenous use -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, Genentech, Inc. · United States · accessed 2026-07-29 · source 1
- MabThera 100 mg / 500 mg Concentrate for Solution for Infusion, and MabThera 1400 mg Solution for Subcutaneous Injection -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Roche Products Ltd · United Kingdom · accessed 2026-07-29 · source 2
- MabThera -- European Public Assessment Report (EPAR) and product informationEuropean Medicines Agency (EMA) · European Union · accessed 2026-07-29 · source 3
- RITUXAN (rituximab for injection) Product MonographHealth Canada product monograph · Canada · accessed 2026-07-29 · source 4
- MabThera -- ARTG registration and Australian Public Assessment ReportTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-29 · source 5
- MabThera (rituximab) New Zealand Data SheetMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-29 · source 6
Brand names by country
Single-ingredient rituximab names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Rituxan10 mg/mL · genentech, inc.
- Riabni100 mg0mL, 500 mg/50mL · amgen, inc
- Truxima10 mg/mL · cephalon, inc.
- Ruxience100 mg0mL, 500 mg/50mL · pfizer laboratories div pfizer inc
United Kingdom
- MabThera (2)MHRA licensed emc smpc confirmed · 100 mg, 500 mg, 1400 mg SC · Roche Products Ltd
Canada
- RITUXAN
- RITUXAN SC
Australia
- MabThera (5)TGA ARTG registered 1998-10-06 confirmed · 100 mg, 500 mg, 1400 mg SC · Roche Products Pty Ltd
New Zealand
- MabThera (6)Medsafe approved confirmed · 100 mg, 500 mg · Roche Products (New Zealand) Limited