Mivacurium Plasma Cholinesterase — FRCA Primary MCQ

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ModeratePharmacology - NeuromuscularMivacurium Plasma CholinesteraseFRCA Primary

Mivacurium is a non-depolarising NMBA with a short duration of action because it is metabolised by:

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Correct answer: D — Plasma cholinesterase (butyrylcholinesterase)

Mivacurium is hydrolysed by plasma cholinesterase (the same enzyme that metabolises suxamethonium). Patients with atypical plasma cholinesterase will have a prolonged block with mivacurium (just as with suxamethonium). Normal duration is 15-20 minutes. It causes dose-dependent histamine release.

Reference: Peck Hill Williams 2014 Pharmacology for Anaesthesia and Intensive Care