Etanercept

Introduction:

Etanercept is a biotechnological product as it is genetically engineered fusion protein.
It is composed of:

1. Two identical chains of the recombinant human TNF-receptor p75 monomer.

2. Fc domain of IgG1 (human immunoglobulin).

These two are fused together.

Mechanism of action:

Etanercept binds two molecules of TNF thereby resulting in no binding of TNF to cellular receptors.

Action:
Etanercept, Infliximab and adalimumab decrease the activity of TNF. TNF is important for immunity system and must rest in the rheumatic synovium for the action to take place.

Pharmacokinetics:
It is given subcutaneously, 25 mg, two times a week. Maximum serum concentration is obtained within 72 hours after parenteral administration. Its half life is 4-6 days.

Therapeutic Uses:
Rheumatic and psoriatic arthritis.

Adverse effects:
No important adverse effects have been found.

Contraindications:
In serious type of infections like sepsis, etanercept should not be given to patient.

NOTE:
Etanercept and methotrexate are more effective when used together (than alone) in slowing the

1. Disease process

2. Improvement in function

3. Stoppage of the symptoms.