Multiple drugs with various mechanisms of actions are used simultaneously during anesthetic practice. Even if the
same dose of drug is administered, diverse individual responses usually occur. These different responses might relate to their pharmacogenetics variation. The pharmacogenetics research network has established a pharmacogenetics knowledge base in order to collect, encode, and disseminate knowledge about the impact of human genetic variations on drug response. For perioperative period,
opioids are the common drugs used with various individual responses. This review shows the pharmacogenetic aspects of four common opioids: morphine, fentanyl, codeine and oxycodone, and their future trends for perioperative pharmacogenetic testing.

Keywords: Pharmacogenetics, Anesthesia, Opioid