Variable cytochrome P450 2D6 expression and metabolism of codeine and other opioid prodrugs: Implications for the Australian anaesthetist

Codeine is a popular opioid prodrug dependent on the activity of the specif ic cytochrome P450 enzyme 206 (CYP2D6). This enzyme catalyses the productio n of the potent analgesic metabolite morphine, but genetic studies have dem onstrated that individuals from different ethnic groups exhibit considerabl e variability in the functional capacities of their expressed CYP2D6 enzyme s, and pharmacological studies have shown many commonly prescribed drugs ca n reduce the action of CYP2D6 enzymes. These findings have significant clin ical implications for the rational prescription of effective analgesia, esp ecially in a multicultural country like Australia.6