Anti-TNF Pharmacology — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

HardRheumatology PharmacologyAnti-TNF PharmacologySCE Rheumatology

A 40-year-old man with psoriatic arthritis and psoriasis has latent tuberculosis identified during pre-biologic screening. Anti-tuberculosis preventive treatment has been commenced following specialist advice. If an anti-TNF agent is subsequently selected, which option has the shortest typical terminal elimination half-life and would therefore show the most rapid decline in circulating drug concentration after discontinuation?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Etanercept

Etanercept is correct. Its typical elimination half-life is approximately 70 hours, or 2.9 days, substantially shorter than those of the other listed TNF inhibitors. Intravenous infliximab has a median terminal half-life of 8–9.5 days, golimumab approximately 12 days, and adalimumab and certolizumab pegol approximately 14 days. Thus, etanercept concentrations would generally decline fastest after treatment is stopped. This pharmacokinetic distinction does not mean that immunological effects cease immediately or establish a fixed clinical “washout period”. The latent-TB history supplies the infection-risk context but does not alter the pharmacokinetic ranking; preventive TB treatment should be started before anti-TNF initiation in accordance with specialist and local recommendations.

Reference: Electronic Medicines Compendium, Enbrel 25 mg Summary of Product Characteristics, sections 4.4 and 5.2, updated 2024: https://www.medicines.org.uk/emc/product/11738/smpc