Rixathon 500 mg per 50 ml is a prescription biosimilar biological medicine containing rituximab. It is a concentrate that must be diluted and administered as an intravenous infusion by an experienced healthcare team in a setting with immediate resuscitation facilities. It targets CD20 positive B cells and is used in specific blood cancers and serious inflammatory diseases.

Approved uses:
• Selected CD20 positive non Hodgkin lymphomas and chronic lymphocytic leukaemia, alone or with the specified chemotherapy regimen.
• Severe active rheumatoid arthritis in adults in combination with methotrexate after inadequate response or intolerance to appropriate disease modifying treatment.
• Severe active granulomatosis with polyangiitis or microscopic polyangiitis with glucocorticoids, and moderate to severe pemphigus vulgaris, according to specialist criteria.

How it works:
Rituximab is a monoclonal antibody that binds CD20 on B lymphocytes and causes depletion of these cells. This can control diseases in which malignant or dysregulated B cells are central to the condition.

Active ingredient and composition:
Each 50 ml vial contains rituximab 500 mg at 10 mg per ml. It also contains sodium citrate, polysorbate 80, sodium chloride, sodium hydroxide, hydrochloric acid and water for injections. Each vial provides approximately 263.2 mg sodium and 35 mg polysorbate 80.

How to use:
For intravenous infusion after dilution only. Never give as an intravenous push or bolus. The dose, dilution, infusion rate, cycle and companion medicines depend on the diagnosis, body surface area, previous treatment and response. Before each infusion, an antihistamine and antipyretic are normally given, with additional medicines when indicated. The patient is closely observed during and after infusion.

Important safety information:
Screen for hepatitis B before treatment and review active or recurrent infection, immune status, heart disease and vaccination plans. Serious infusion reactions, severe infections, hepatitis B reactivation, tumour lysis syndrome, severe skin reactions and progressive multifocal leukoencephalopathy can occur. Live vaccines are generally avoided. Patients treated for inflammatory disease should carry the alert card. Effective contraception is required during treatment and for 12 months afterward where pregnancy is possible.

Medical disclaimer:
This medicine is not suitable for self diagnosis or unsupervised treatment. Use it only for the person and condition for which it was prescribed, follow the local package leaflet, and seek urgent medical help for a severe allergic reaction, breathing difficulty, fainting, or rapidly worsening symptoms.