Opioid analgesia: perspectives on right use and utility.

The ability of opioids to effectively and safely control acute and cancer pain has been one of several arguments used to support extending opioid treatment to patients with chronic pain, against a backdrop of considerable caution that has been based upon fears of addiction. Of course, opioids may cause addiction, but the "principle of balance" may justify that "...efforts to address abuse should not interfere with legitimate medical practice and patient care." Yet, situations are increasingly encountered in which opioid-maintained patients are refractory to analgesia during periods of pain, or even during the course of chronic treatment. The real question is whether analgesic efficacy of opioids can be maintained over time. Overall, the evidence supporting long-term analgesic efficacy is weak. The putative mechanisms for failed opioid analgesia may be related to tolerance or opioid-induced hyperalgesia. Advances in basic sciences may help in understanding these phenomena, but the question of whether long-term opioid treatment can improve patients' function or quality of life remains a broader issue. Opioid side effects are well known, but with chronic use, most (except constipation) subside. Still, side effects can negatively affect the outcomes and continuity of therapy. This paper addresses 1) what evidence supports the long-term utility of opioids for chronic pain; 2) how side effects may alter quality of life; 3) the nature of addiction and why it is different in pain patients, and 4) on what grounds could pain medication be denied? These questions are discussed in light of patients' rights, and warrant balancing particular responsibilities with risks. These are framed within the Hippocratic tradition of "producing good for the patient and protecting from harm," so as to enable 1) more informed clinical decision making, and 2) progress towards right use and utility of opioid treatment for chronic pain.