CYP2D6 Polymorphism — FRCA Primary MCQ
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Correct answer: A — Exhibits significant genetic polymorphism affecting codeine and tramadol metabolism
CYP2D6 metabolises approximately 25% of all drugs including codeine (to morphine) and tramadol (to O-desmethyltramadol). It exhibits significant genetic polymorphism: poor metabolisers (7% Caucasians / 1% Asians) and ultra-rapid metabolisers (1-2% Caucasians / up to 29% in some African populations). CYP2D6 is largely non-inducible.
Reference: Peck Hill Williams 2014 Pharmacology for Anaesthesia and Intensive Care