The Relationship of Opioid Treatment in Chronic Pain Conditions

Abstract

An area of scientific understanding that remains unexplained is the effect of chronic pain conditions on the brain reward response to opioids. Substance misuse remains one of the most baffling areas of scientific evaluation, identification, and intervention given that very little is known about the mechanisms differentiating inevitable physiologic responses to opioids and dysfunctional or abnormal responses to long-term opioid administration. The effects of opioids on the brain reward system in persons with chronic pain is of significance to clinicians. Given the paucity of information available on opioid therapeutic use versus misuse in this population, however, the clinician is left to develop subjective conclusions about differentiation. Inevitable opiate effects include the linked concepts of tolerance to opioids, development of withdrawal phenomena, hyperalgesia, and pharmacologic resistance to the antinociceptive properties of opioids. This article evaluates current knowledge regarding relationships...