Long-term opioid therapy for chronic pain and the risk of opioid addiction.

INTRODUCTION There has been a constant struggle to define the role of opioids in medical therapy, due to their potential for misuse, overuse, and addiction since pain is a completely subjective sensation, not amenable to objective measurement, and is intimately tied to emotion and the patient’s psychological well-being. Thus the medical decision to administer an opioid analgesic is an attempt to balance the potential for pain relief, and the reliability of the patient’s reporting, against the potential for harm. The decision-making process is less complicated when dealing with acute traumatic injury or surgical trauma. However, with many chronic pain conditions, the etiology or severity of the patient’s pain is less obvious. In the majority of situations, a physician does not initiate opioid therapy with the intention of continuing it for months or years, but many patients will continue to seek opioids for relief of pain which becomes chronic. Until 1990, chronic use of opioid analgesics was widely discouraged, with most physicians trained to taper their patients off opioid medication after an acute treatment trial. The paradigm began to shift as the movement to improve cancer pain treatment became successful with aggressive opioid prescribing. The success of aggressive opioid therapy for cancer pain treatment led to a spill over into chronic non-cancer pain treatment, spurred on by industry-supported continuing medical education programs. As high-dose opioids became more available in the community, it was accompanied by a pattern of escalating drug diversion, opioid misuse, accidental opioid overdose, and deaths that continued to climb through the past decade. (Figure 1)1 Accidental opiate overdose deaths from prescription opioids began to far exceed deaths attributed to illicit drugs of abuse, such as heroin and cocaine. Nationally, accidental drug overdose deaths surpassed deaths from motor vehicle accidents, reaching a peak of 16,917 deaths from prescription opioids in 2011 (http://www.cdc.gov/homeandrecreationalsafety/overdose/ facts.html). During the period from 2009–12, Rhode Island Figure 1. Rates of opioid pain reliever (OPR) overdose death, OPR treatment admissions, and kilograms of OPR sold – United States, 1999–2010.1