Pharmacogenetics of opioids: a narrative review.

Advances in the field of pharmacogenomics have resulted in the discovery of some important single-nucleotide polymorphisms which are found to be associated with opioid dose variability. This, to a large extent, explains genetic variability in the analgesic dose of opioids. These polymorphisms are found in various areas relevant to pain perception, including the nociceptive and antinociceptive pathways, drug receptors, drug-metabolising enzymes and drug efflux molecules. An in-depth knowledge of single-nucleotide polymorphisms can help clinicians to address interindividual variability in opioid dosing and requirements. In the era of precision medicine, these genetic markers can also help us to design prognostic tools to accurately predict the analgesic dose of opioids.