TAMPA – Levorphanol appears to be an attractive option for the treatment of refractory pain that does not respond to other opioids, based on a case series of 31 patients presented at the annual meeting of the American Academy of Hospice and Palliative Medicine and the Hospice and Palliative Nurses Association.
Dr. John P. McNulty of the Palliative Care Institute of Southeast Louisiana presented a case series of 20 of 244 patients with chronic, nonmalignant pain from a palliative care clinic and 11 of 1,508 terminally ill patients with severe chronic pain enrolled in hospice care during a 5-year period. These patients were treated with levorphanol when pain did not respond adequately to other opioids, including methadone. Roughly half of the patients reported excellent relief (52%). Another 22% reported fair pain control, yielding a response rate of 74%.
Levorphanol has been reported to provide analgesia at doses that suggest it does not act like other pure agonist opioids. It has been proposed that levorphanol acts on both opioid receptors and N-methyl-D-aspartate (NMDA) receptors, which might account for this effect.
The drug has a number of advantages. It acts on mu, kappa, and delta opioid receptors and is an NMDA receptor antagonist. The drug relieves neuropathic pain, has a long half-life, and can be administered every 6–8 hours.
Levorphanol's disadvantages include the lack of a parenteral formulation. It is not actively marketed, so many physicians are not aware that it is available. “I would suggest, based on this, that if methadone works then levorphanol might be an option,” Dr. McNulty said. “We are using it for our hospice patients as a second-line drug.”
Dr. McNulty disclosed that he had no relevant financial relationships.