The role of dextromethorphan in pain control

Purpose: To review the clinical benefits of dextromethorphan (DM) in pain m anagement, describe its neuropharmacological properties. Source: A Medline search was made for experimental and clinical data on DM use from 1967 to date using keywords nociception, acute and chronic pain co ntrol, N-methyl-D-aspartate, antagonists, dextromethorphan. Principle findings: The 930 DM citations mostly described its antitussive, metabolic and toxicological aspects, animal studies and its possible role i n minimizing post-brain ischemia complications in humans. The use of DM in acute pain revealed eight original studies involving 443 patients, as well as two preliminary reports and our own unpublished data on 513 patients. Mo st of the 956 patients had general anesthesia. Eight studies (154 patients) and one case report dealt with chronic pain management. This N-methyl-D-as partate (NMDA) receptor antagonist binds to receptor sites in the spinal co rd and central nervous system, thereby blocking the generation of central a cute and chronic pain sensations arising from peripheral nociceptive stimul i and enabling reduction in the amount of analgesics required for pain cont rol. DM attenuated the sensation of acute pain at doses of 30-90 mg, withou t major side effects, and reduced the amount of analgesics in 73% of the po stoperative DM-treated patients, Studies in secondary pain models in health y volunteers and in various types of chronic pain showed DM to be associate d with unsatisfactory pain relief. Conclusion: DM attenuates acute pain sensation with tolerable side effects. Its availability in oral form bestow advantages over other NMDA antagonist s.