Genetics and implications in perioperative analgesia.

The wide range of patient responses to surgical pain, opioids, and anesthetic agents has puzzled anesthesiologists for many years. Much of the variation has been attributed to differences in patient size, technique, or prior drug use. However, recent genetic testing has revealed exciting clues into the basis for these variances, allowing us to start to predict which patients may have difficulties and start to select medications more rationally. In this manuscript, we discuss genetics and pain perception, genetic predisposition to pain, drug metabolism interactions, ethnogenetics, opioid metabolism, opioid receptors, genetic-related peri-anesthetic toxicity, as well as a clinical approach and a discussion regarding the future of genetic testing and anesthesia.