From the Guidelines
Rituximab is a monoclonal antibody medication that works by targeting and destroying B cells that have the CD20 protein on their surface, and its typical uses include treating non-Hodgkin lymphoma, chronic lymphocytic leukemia, and autoimmune conditions, with a common dosing regimen of 375 mg/m² administered as an intravenous infusion once weekly for four weeks. Rituximab binds to the CD20 protein, triggering cell death through multiple mechanisms including antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and direct induction of apoptosis 1. The medication is used to treat various conditions, including non-Hodgkin lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, granulomatosis with polyangiitis, and microscopic polyangiitis. Some key points to consider when using rituximab include:
- Typical dosing regimens vary by condition, with 375 mg/m² administered as an intravenous infusion once weekly for four weeks being common for lymphoma 1
- Premedication with acetaminophen and an antihistamine is typically recommended to reduce infusion reactions 1
- Patients should be screened for hepatitis B before starting treatment, as rituximab can reactivate the virus 1
- The medication's B-cell depleting effects can last for 6-12 months after treatment, providing sustained therapeutic benefit but also requiring careful monitoring for infections during this period 1. It is essential to carefully monitor patients for potential side effects and complications, including infusion reactions, infections, and hepatitis B reactivation, and to adjust the dosing regimen as needed to minimize these risks 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Mechanism of Action
- Rituximab is a human-mouse chimeric monoclonal antibody that targets the B-cell CD20 antigen, causing rapid and specific B-cell depletion 2.
- The cytotoxic effects of rituximab on CD20-positive malignant B cells involve complement-dependent cytotoxicity, complement-dependent cellular cytotoxicity, antibody-dependent cellular cytotoxicity, and induction of apoptosis 3, 4, 5.
- Rituximab can also sensitize tumor cells to the effects of conventional chemotherapeutic drugs 3, 5.
Typical Uses
- Rituximab is used to treat low-grade or follicular, relapsed or refractory, CD20-positive B-cell non-Hodgkin's lymphoma (NHL) 2, 3.
- It is also used in combination with standard chemotherapy for aggressive NHL, such as diffuse large B-cell lymphoma 2, 3.
- Rituximab has been investigated for use in autoimmune disorders, including rheumatoid arthritis, immune thrombocytopenic purpura, autoimmune hemolytic anemia, systemic lupus erythematosus, and multiple sclerosis 2, 6.
Dosing Regimens
- The typical dosing regimen for rituximab is 375 mg/m(2) intravenously once weekly for 4 weeks 3.
- Peak serum concentrations of rituximab increase with each successive infusion, and the elimination half-life also increases 3.
- The pharmacokinetic properties of rituximab are characterized by wide inter-individual variability, and serum drug concentrations are correlated with clinical response 3.