Mabrix 500 IV Infusion

Indications

Rituximab is a specialist medicine used for:

• Some types of non-Hodgkin lymphoma and chronic lymphocytic leukaemia (cancers of white blood cells called B cells), often together with chemotherapy.
• Moderate to severe rheumatoid arthritis, usually with Methotrexate, when other treatments have not worked well enough.
• Granulomatosis with polyangiitis and microscopic polyangiitis (types of blood vessel inflammation).
• Moderate to severe pemphigus vulgaris (a blistering skin disease).

How It Works

Rituximab is a monoclonal antibody, a laboratory-made protein that targets one specific thing in the body. It attaches to a marker called CD20 on the surface of B cells and helps the immune system destroy them. This kills cancerous B cells and calms the overactive immune response in some autoimmune diseases.

Dosage and Administration

Rituximab is given only by a doctor or nurse in a hospital or treatment centre, as a slow drip into a vein (infusion). The dose and schedule depend on the illness, body size and other treatments, and are decided by the specialist. The medicine is taken as prescribed. Before each infusion, medicines such as Paracetamol, an antihistamine and often a steroid are usually given to reduce infusion reactions. Patients are watched closely during and after each infusion.

Interactions

• Live vaccines should not be given during treatment or while B cells are low; other vaccines may work less well.
• Other medicines that weaken the immune system increase the risk of infection.
• Blood pressure medicines may be paused for some hours before the infusion, because blood pressure can drop during it.

Tell the doctor about every medicine and supplement you take.

Contraindications

• Allergy to rituximab or to mouse proteins.
• Active, severe infection.
• A severely weakened immune system.
• Severe heart failure or severe uncontrolled heart disease (for rheumatoid arthritis and other non-cancer uses).

Side Effects

Common: infusion reactions (fever, chills, shivering, rash, itching, headache, flushing), especially with the first infusion; infections such as colds, chest and urine infections; tiredness; low white cell, red cell or platelet counts.

Get urgent medical help if you have:

• Breathing difficulty, wheezing, swelling of the face or throat, or feeling faint during or after an infusion.
• Fever, chills or other signs of a serious infection.
• Yellow skin or eyes or dark urine (possible hepatitis B flare-up).
• New confusion, memory problems, trouble walking or speaking, or vision loss (rare brain infection).
• Severe skin blistering or peeling, or mouth sores.
• Chest pain or an irregular heartbeat.

Pregnancy and Lactation

Rituximab should not be used in pregnancy unless the specialist decides the benefit outweighs the risk, because it can lower B cells in the baby. Women who can become pregnant should use effective contraception during treatment and for 12 months after the last dose. Do not breastfeed during treatment unless the doctor advises it is safe.

Precautions and Warnings

• You will be tested for hepatitis B before starting; it can flare up during or after treatment.
• Tell the doctor about heart disease, lung disease, past or current infections, or recent vaccines.
• Infection risk can stay raised for months after the last dose.
• Have routine blood tests as advised.

Overdose

Because it is given in hospital by trained staff, overdose is unlikely. If too much is given, the patient is monitored and treated for any reaction or infection.

Therapeutic Class

Monoclonal antibody (anti-CD20); anticancer and immunosuppressant medicine.

Storage

Store in a refrigerator at 2 to 8°C, protected from light. Do not freeze. It is normally stored and prepared by the hospital pharmacy.