Chin Hang Yiu

1 Introduction Opioids remain a central component of post-operative pain in opioid-naïve patients, with over 90% of patients receiving one or more opioids after surgery [1]. Despite increasing emphasis on opioid stewardship, more than 10% of cancer survivors reported persistent opioid use 1 year after surgery [2].

What is the current knowledge on the topic? ○ Individuals with poor or intermediate thiopurine methyltransferase (TPMT) enzyme activity are at increased risk of moderate to severe myelosuppression following thiopurine treatment. TPMT testing can guide dose adjustments or alternative treatments to reduce this risk.

What is the current knowledge on the topic? ○ International consensus groups such as the Clinical Pharmacogenetics Implementation Consortium provide access to a range of actionable pharmacogenetic guidelines and resources for specific drug–gene pairs. However, pharmacogenetic testing implementation and utilization of these resources can be limited by government and patient-level financial inaccessibility.