Rituximab
Looking for the plain-language version? See the patient version of this page.
Dosing and administration[2]
IV infusion with premedication (corticosteroid, antihistamine, acetaminophen). Screen for hepatitis B (reactivation risk, including fatal cases) and tuberculosis before starting.
| Indication | Starting dose | Titration and maximum |
|---|---|---|
| Rheumatoid arthritis | Two 1000 mg IV infusions given 2 weeks apart (days 1 and 15), repeated every 6 months or by disease activity, usually with methotrexate. | Retreat based on clinical response, typically no sooner than every 16 to 24 weeks. |
| ANCA-associated vasculitis | 375 mg/m2 IV weekly for 4 weeks (induction), or 1000 mg x 2; maintenance regimens follow. | Per protocol for induction and maintenance. |
Monitoring
- Hepatitis B screening (and monitoring or prophylaxis for carriers) and TB screening before starting.
- Monitor infusion reactions, CBC, and immunoglobulin levels; watch for serious and opportunistic infection, including rare PML.
- Assess for hypogammaglobulinaemia with repeated courses.
Contraindications
- Active severe infection.
- Active hepatitis B.
- Severe active heart failure (relative).
Key interactions
- Do not combine with other biologics.
- Live vaccines should be given before treatment, not during.
- Increased infection risk with other immunosuppressants.
Clinical notes
How it is used in lupus
Used for refractory SLE and refractory lupus nephritis as an anti-CD20 B-cell-depleting option.[1]
Common side effects
Infusion reactions and increased infection risk occur; repeated courses can lower immunoglobulin levels. Described from background clinical knowledge and the Table 5 monitoring note; reconcile with the product monograph.
Tests and monitoring
CBC with differential at 3 months, then every 6 months. Assess IgG levels every 6 months.[1]
Before you start
Screen for hepatitis B, tuberculosis, and HIV before starting. As a B-cell-depleting therapy, it carries a higher hepatitis B reactivation risk, so antiviral prophylaxis is used for higher-risk hepatitis B profiles. Address vaccination beforehand; live vaccines are not given during treatment.[1]
Important cautions
Reproductive-safety data are limited; individualise, with full guidance maintained on the pregnancy record. Avoid live vaccines during treatment.
References
- Sammaritano LR, Askanase A, Bermas BL, et al. 2025 American College of Rheumatology (ACR) Guideline for the Treatment of Systemic Lupus Erythematosus. Arthritis Care Res (Hoboken). 2025. doi:10.1002/acr.25690 https://doi.org/10.1002/acr.25690
- RITUXAN (rituximab) Product Monograph. Health Canada authorized product monograph. https://health-products.canada.ca/dpd-bdpp/