BACKGROUND AND OBJECTIVES: Due to the objective of the outpatient setting and to routinely used drugs, this study aimed at reviewing and updating the knowledge about opioid receptors and worked as a study complement after a lecture presented to team members. CONTENTS: We have reviewed from historical aspects to most recent developments about opioid receptors, in addition to describing subtypes and action mechanisms. For such, Pubmed-indexed references were queried. CONCLUSION: After reviewing current literature data, we have concluded that there is still a lot to be researched about the topic, aiming at safer drugs, and new biomolecular techniques are still needed.
History of medicine; Morphine; Morphine receptors; Opioid antagonists; Opioid receptors; Opioids; Opium; Poppy