Pharmacogenomic considerations in the opioid management of pain

Physicians continue to struggle with the clinical management of pain, in part because of the large interindividual variability in the efficacy, occurrence of side effects and undesired severe adverse drug reactions from the prescribed analgesics. Pharmacogenomics, the study of how an individual's genetic inheritance affects the body's response to medications, has an important role and can explain some of this interindividual variability. Genetic identification of known variant alleles that affect the pharmacokinetics or pharmacodynamics of medications used for pain management can enable physicians to select the appropriate analgesic drug and dosing regimen for an individual patient, instead of empirical selection and dosing escalation. In this article, clinically relevant pharmacogenomic targets for the management of opioid pain, including efflux transporters, proteins that metabolize drugs, enzymes that regulate the neurotransmitters that modulate pain, and opioid receptors, will be reviewed.