Perspectives on the medical use of drugs of abuse.

The treatment of severe pain requires the use of potent opioid analgesic medications. Many patients with opioid sensitive pain are being undermedicated. This results in increased morbidity and needless suffering. The most important reason for this undertreatment is the fear of addiction engendered by opioids, a fear that is greatly out of proportion to the real risk. The risk of addiction is greatly overestimated in part because many people do not understand the distinctions between drug abuse and drug addiction, on the one hand, and physical dependence and tolerance, on the other. Dependence and tolerance are virtually inevitable outcomes of long-term opioid use, but they are neither sufficient to cause addiction nor the equivalent of it. Indeed, the evidence shows that only a tiny fraction of patients treated with opioids become addicted. There is little risk of addiction for those patients receiving properly administered opioids for pain.