skip to main content

Opioid Lipid Solubility — FRCA Primary MCQ

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

HardPharmacology - AnalgesicsOpioid Lipid SolubilityFRCA Primary

Which feature best explains remifentanil’s rapid offset after an infusion is stopped?

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

Reveal the answer and explanation

Correct answer: AMetabolism by non-specific blood and tissue esterases

The best answer is “Metabolism by non-specific blood and tissue esterases”. Remifentanil is rapidly metabolised by non-specific blood and tissue esterases to an essentially inactive metabolite. Its offset is therefore not dependent on hepatic metabolism, renal elimination of unchanged drug, or slow receptor dissociation. Protein binding does not explain the defining rapid offset.

Reference: Remifentanil 1 mg, Summary of Product Characteristics: https://www.medicines.org.uk/emc/product/794/smpc