Etanercept

See Tumor Necrosis Factor Inhibitor
Etanercept is a recombinant soluble Antibody against human Tumor Necrosis Factor alpha
1. Etanercept has a unique structure among modern TNF Inhibitors which are primarily monoclonal antibodies
Etanercept is a dimeric fusion Protein (2 components)
1. Extracellular Ligand-binding region of TNF receptor
2. Fc domain of Immunoglobulin G (IgG)
Etanercept binds circulating TNF and inhibits TNF binding to TNF cell surface receptors
1. Blocks TNF-mediated inflammatory activity

Etanercept (Enbrel)
1. Original prototype drug with release in 1998 for Rheumatoid Arthritis, with expanding indications since
Multiple biosimilar agents (Erelzi, Eticovo) are available
1. However, Biosimilars are not considered interchangeable (consistently use same agent)

See Monoclonal Antibody for preparation for use
Background
1. Injection sites include thigh, Abdomen or upper, outer arm (rotate injection sites)
2. Available as a Preloaded vial or syringe
3. Refrigerate and protect from light
4. Stable at room Temperature for up to 14 days
5. Allow to warm to room Temperature for 15 to 30 minutes before injection (decreased pain)
Rheumatoid Arthritis, Psoriatic Arthritis or Ankylosing Spondylitis
1. Inject 50 mg SQ weekly
Plaque Psoriasis
1. Start 50 mg SQ twice weekly for 3 months
2. Next 50 mg SQ weekly
Child (weight <63 kg)
1. Indicated in Juvenile Idiopathic Arthritis (age >2 years) and plaque Psoriasis (age >4 years)
2. Use adult dosing for weight >=63 kg
3. Inject 0.8 mg/kg SQ weekly

See TNF Inhibitor
TNF Inhibitors predispose to serious infections and malignancy
Prepare for TNF Inhibitor use with infection screening (e.g. Tuberculosis) and Immunizations
1. See Monoclonal Antibody

Considered safe in Lactation
Pregnancy
1. May use in pregnancy (any trimester) if indicated and benefit outweighs risk
2. Fetal exposure risk increases after 20 weeks