API

Rituximab (500mg)

Drug classification

Monoclonal antibodies (anti-CD20 monoclonal antibody).

Dosage form

Concentrate for solution for intravenous infusion.

API strength per dosage

500 mg per 50 mL vial

Dose

For adults: 375 mg/m² IV weekly for 4 weeks (lymphoma) or 1000 mg IV on days 1 and 15 (rheumatoid arthritis). Pediatric dosing: 375 mg/m² IV weekly for 4 weeks. Dose adjustments may be required in renal or hepatic impairment; consult specialist guidance.

Mechanism of action

Indications

Non-Hodgkin lymphoma (NHL) Rheumatoid arthritis Blood cancer (Chronic lymphocytic leukemia) Granulomatosis with polyangiitis Microscopic polyangiitis

Side effects

Headache Weakness Infection Chills Decreased white blood cell count neutrophils Fever Infusion site reaction Lymphopenia Abdominal pain Back pain

Pregnancy category

Category C

Precautions

Infusion reactions, severe infections, hepatitis B reactivation, progressive multifocal leukoencephalopathy, tumor lysis syndrome, cardiac events, cytopenias, hypersensitivity, premedication requirement, monitoring during infusion, avoid live vaccines, caution in pregnancy and lactation, renal and hepatic impairment, risk of bowel obstruction or perforation, secondary malignancies.

Contraindications

Hypersensitivity to rituximab or murine proteins, active severe infections, severe active hepatitis B infection.