Can levorphanol be used like methadone for intractable refractory pain?

Background: Levorphanol has been reported to provide analgesia at doses that suggest it does not act like other pure agonist opioids. A dual effect of action on both opioid receptors and n-methyl, d-aspartate (NMDA) receptors has been proposed to be responsible for this effect.

Method: Case series of patients treated with levorphanol when pain did not respond adequately to other opioids, including methadone.

Results: During a 5-year period in a single palliative medicine practice, 20 of 244 patients with chronic nonmalignant pain in a palliative care clinic and 11 of 1508 terminally ill patients enrolled in hospice care whose severe chronic pain was not relieved by treatment with other opioids were treated with oral levorphanol. Of those 31 patients, 16 (52%) reported excellent relief of pain and 7 (22%) reported fair relief for a total response rate of 74%.

Discussion: These results suggest that levorphanol has a role in the treatment of pain syndromes that are refractory to other opioids. The pattern of relief seen in this case series is similar to that reported for methadone. Could it be that levorphanol may have a role like methadone for pain that is poorly controlled with other pure agonist opioids? We summarize what is known about levorphanol and provide a table for converting other opioids to levorphanol that was used for this case series.