Etanercept !

A decoy TNF receptor joined to an antibody tail; it soaks up TNF. Injected for rheumatoid, psoriatic and spinal arthritis and psoriasis, not for bowel disease.

Updated 2026-11-01

Class: TNF inhibitors
Target: Tumour necrosis factor alpha (TNF-α)
ATC code: L04AB01

Tumour necrosis factor alpha (TNF-α)Etanercept

The figure shows TNF bound to the extracellular part of TNF receptor 2; etanercept is that same receptor part fused to an IgG1 Fc, so it grips TNF the same way.

Target in 3D: Tumour necrosis factor alpha (TNF-α). PDB structure 3ALQ (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

Etanercept is a fusion protein: two copies of the extracellular ligand-binding part of the human p75 TNF receptor (TNFR2) joined to the Fc portion of human IgG1. It acts as a soluble decoy receptor that captures TNF before it reaches cell receptors. Unlike the antibodies, it is not approved for Crohn disease or ulcerative colitis.

TNFR2 ectodomain fused to an IgG1 Fc
Acts as a soluble decoy receptor
Traps TNF-α before it reaches cells
Joint and skin inflammation falls

Pharmacokinetics

Absorption: Subcutaneous injection; absorbed slowly
Metabolism: Broken down like other proteins

Indications

Rheumatoid arthritis Rheumatoid arthritis →
Polyarticular juvenile idiopathic arthritis Juvenile idiopathic arthritis →
Psoriatic arthritis Psoriatic arthritis →
Ankylosing spondylitis Ankylosing spondylitis →
Chronic plaque psoriasis Psoriasis →

Adverse effects

Common

Injection-site reactions (redness, itching, bruising)
Upper respiratory infections

Contraindications

Active serious infection, including active tuberculosis
Hypersensitivity to etanercept

Key interactions

Anakinra or abatacept: More serious infections without added benefit; not combined.
Live vaccines: Risk of infection by the vaccine strain; avoided during treatment.
Other immunosuppressants (glucocorticoids, methotrexate, azathioprine): Additive risk of infection; azathioprine or mercaptopurine with a TNF blocker has been linked to hepatosplenic T-cell lymphoma.

What is monitored

Latent tuberculosis test before starting, and watch for active TB during and after treatment even if the test was negative
Hepatitis B screening before starting
Signs of infection at every visit
Skin checks for cancer

Administration and safety

Subcutaneous injection, rotating sites (thigh, abdomen, upper arm).
Some devices contain latex in the needle cover; latex allergy is asked about.
Kept refrigerated in its carton.

Nursing care

Confirm that the latent TB test and hepatitis B screening are done (and treated if positive) before the first dose.
Do not give the dose during an active infection; report fever, cough, night sweats or weight loss.
Check that vaccines are up to date before starting; live vaccines are avoided during treatment.
Ask about heart failure and neurological disease before starting.
In people with diabetes, watch blood glucose: other diabetes medicines may need review.

Pregnancy and breastfeeding

If it is used in pregnancy, the baby's doctor is told, because some vaccines for the infant may need to be given later than usual.

Test yourself

Think of the answer, then tap the question to see it.

What is the structure of etanercept?

Two extracellular domains of the p75 TNF receptor (TNFR2) fused to the Fc portion of human IgG1: a soluble decoy receptor.

Which TNF inhibitor is not approved for inflammatory bowel disease?

Etanercept; infliximab, adalimumab, certolizumab pegol and golimumab have bowel indications.

What should be checked before the first etanercept dose?

Latent tuberculosis, hepatitis B, active infections, vaccines (no live ones during treatment), and history of heart failure or demyelinating disease.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: Etanercept Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2024); Altered Immunocompetence | Vaccines & Immunizations | CDC (Centers for Disease Control and Prevention (CDC), 2024); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 39 (McGraw Hill, 2023); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.