G6PD Avoid Prilocaine — FRCA Primary MCQ

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

HardPharmacology - AnalgesicsG6PD Avoid PrilocaineFRCA Primary

After a large prilocaine regional block, a patient develops cyanosis with a normal PaO2. Which complication is most likely?

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

Reveal the answer and explanation

Correct answer: A — Methaemoglobinaemia caused by prilocaine metabolites

The best answer is “Methaemoglobinaemia caused by prilocaine metabolites”. Prilocaine can cause methaemoglobinaemia because of its metabolites, particularly after large or repeated doses. It may produce cyanosis and impaired oxygen carriage despite a normal arterial oxygen tension. Allergy, hypovolaemia, malignant hyperthermia and aspiration have different clinical patterns and mechanisms.

Reference: Prilocaine hydrochloride 1% injection, Summary of Product Characteristics: https://www.medicines.org.uk/emc/product/870/smpc