G6PD Deficiency Drug Avoidance — FRCA Final MCQ

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ModeratePreoperative AssessmentG6PD Deficiency Drug AvoidanceFRCA Final

A 35-year-old woman (ASA I) with known G6PD deficiency requires GA for appendicectomy. Which commonly used perioperative drug must be avoided?

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Correct answer: A — Fentanyl

Prilocaine (a component of EMLA cream and used for IV regional anaesthesia) is an oxidising agent that can trigger severe haemolysis in G6PD-deficient patients. Other drugs to avoid: methylene blue (the treatment for methaemoglobinaemia – creates a paradox in G6PD patients as methylene blue both causes and treats methaemoglobinaemia), sulphonamides, dapsone, rasburicase, and certain antimalarials. Paracetamol is safe at standard doses. Propofol, fentanyl, and rocuronium are all safe. If the patient does develop methaemoglobinaemia and methylene blue is contraindicated, treatment options include: ascorbic acid, exchange transfusion, or hyperbaric oxygen.

Reference: BNF – 2025 – G6PD deficiency: drugs to avoid; RCOA – 2023 – Haematological disorders