Enbrel

What is it?

A preparation which is a Tumour Necrosis Factor-a (TNF-a) inhibitor - (TNF-a is an inflammatory cytokine substance that stimulates cells in the synovial membrane surrounding joints to produce harmful enzymes that erode joints in rheumatoid arthritis). It is available as a powder in a vial, together with a solvent in a prepared syringe, containing 25mg of etanercept, for reconstitution and injection.

Medical Uses

Active rheumatoid arthritis that has not responded to other Disease- modifying antirheumatic drugs (DMARDs), including methotrexate; active polyarticular-course juvenile arthritis that has not responded to methotrexate treatment. Also, severe, progressive rheumatoid arthritis in adults who have not received methotrexate treatment.

Dosage

Adults, 25mg by subcutaneous injection twice each week; children aged 4 to 18 years, 0.4mg per kg of body weight by subcutaneous injection twice each week, allowing 3 to 4 days between doses. The maximum single dose for children is 25mg.

Special Care

Patients with depressed immune system, history of, or predisposition to infections, known exposure to varicella (chickenpox) virus; certain central nervous system demyelinating disorders, including inflammation of optic nerve, multiple sclerosis - risks must be carefully weighed against benefits. Certain abnormal blood changes or history of such - patients should be advised of warning signs and symptoms; if suspected, blood tests must be performed and if confirmed, drug should no longer be used.

Avoid Use

Pregnancy (women of childbearing age must use effective contraception), breastfeeding, infection, risk of sepsis.

Possible Drug and Food Interactions

Live vaccines.

Known Side Effects

Central nervous system demyelinating disorders such as optic nerve inflammation and multiple sclerosis, heart and circulatory effects, malignancies, seizures, pancreatitis, gastrointestinal bleeding, disorders of blood and lymph system, headache, fever, weakness, depression, infection, reactions at injection site, dizziness, acid indigestion, pains in abdomen, breathlessness, swelling, bursitis (inflammation of bursa - connective tissue surrounding joint). In rare cases, aplastic anaemia or pancytopenia (severe reduction in all elements of the blood) which can be fatal, SLE (systemic lupus erythematosus). All adverse side effects should be reported to the Committee on the safety of Medicines (CSM).