Etomidate Injection Pain — FRCA Primary MCQ

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ModeratePharmacology - Intravenous AnaestheticsEtomidate Injection PainFRCA Primary

Etomidate causes pain on injection primarily due to:

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Correct answer: B — The propylene glycol solvent in the original formulation

Pain on injection with etomidate is primarily attributed to the propylene glycol solvent (35% v/v) in the original formulation. The lipid emulsion formulation of etomidate significantly reduces injection pain. Propylene glycol also causes haemolysis and venous irritation at the injection site.

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