Compared with morphine, oxycodone is associated with a reduced frequency of adverse effects, particularly delirium.42,43,44 These characteristics, combined with increased liability concerns and lack of pharmacogenetic testing, suggest a shift in analgesic utilization toward oxycodone as a preferable option in pediatric patients in the US but not in Canada.21 Unlike with codeine, the CYP2D6 genotype is not strongly associated with observed oxycodone response,45,46,47 but oxycodone and its active metabolite oxymorphone can lead to opioid dependence,48,49 raising reasonable concerns. The gene discussed is CYP2D6; the disease is delirium.