Current pharmacotherapy of chronic pain

Advances in basic and clinical research have greately expanded the options for analgesic pharmacotherapy. There are three broad categories of analgesi c medications: (1) nonopioid analgesics, which includes the nonsteroidal an ti-inflammatory drugs (NSAIDs), acetaminophen, dipyrone, and others; (2) a diverse group of drugs known a the "adjuvant analgesics," which are defined as "drugs that have primary indications other than pain but may be analges ic in selected circumstances;" and (3) opioid analgesics. The advent of hig hly selective COX-2 inhibitors has generated excitement because of the poss ibility that these new NSAIDs will be much safer than previous COX inhibito rs. However, the cost-benefit of using these relatively more expensive drug s versus other NSAIDs plus gastroprotective therapies needs to be determine d. Adjuvant analgesics can be grouped into four major classes according to their use: multipurpose, neuropathic pain, musculoskeletal pain, and cancer pain. There has been a dramatic increase in the number of these drugs duri ng the past two decades and they now play an important role in the manageme nt of chronic pain. Pain specialists are now using opioids for chronic nonm alignant pain in addition to the traditional use for acute and cancer pain. This change in practice evolved from recognition that selected patients wi th chronic noncancer-related pain can experience sustained analgesia and fu nction better with these drugs, without developing an addictive disorder. T he combination of opioids and other drugs, such as an N-methyl-D-aspartate- receptor antagonist, may improve the balance between analgesia and adverse effects. J Pain Symptom Manage 2000; 19:S16-S20. (C) U.S. Cancer Pain Relie f Committee, 2000.