Neuropathic pain increases analgesic needs in children with cancer

In children dying from cancer, neuropathic pain is associated with greatly increased analgesic needs, particularly during the last 3 days of life, according to recent study findings. However, the findings also suggest that adding methadone to the treatment regimen can improve pain control in these children.

Dr. Michael R. DeBaun, from Washington University in St. Louis, and Matt Dougherty, from Johns Hopkins University in Baltimore, evaluated pain control in 18 children with terminal cancer, focusing on opioid and benzodiazepine dosages during the last 3 days of life. The study group included 12 patients with neuropathic pain and 6 without such pain.The average morphine dose 3 days before death was 231 mg/kg per day in the neuropathic group, but only 3.0 mg/kg per day in the nonneuropathic group, the authors report in the April issue of the Journal of Pediatrics. Furthermore, in only the neuropathic group, morphine and benzodiazepine doses increased significantly from 3 days before death to the day of death.Based on the finding that opioid requirements were, in fact, increased in children with neuropathic pain, the authors decided to conduct a small prospective study to determine if methadone treatment could reduce opioid needs and enhance pain control. This substudy involved 3 patients who started methadone treatment within 7 days of pain onset.Methadone treatment led to a major reduction in opioid needs during the last 3 days of life, the authors note. The average dose of morphine derivatives (including methadone) 3 days before death was 3.85 mg/kg per day, which was similar to the amount previously identified in the nonneuropathic group. In addition, treatment with methadone prevented the dramatic rise in opioid needs that occurred on the day of death.”After reviewing the literature, I realized that there is no standard way to treat neuropathic pain in children,” Dr. DeBaun told Reuters Health. “After seeing the benefits of methadone in the current trial and in subsequent patients, I don’t think I could, in good conscious, do a trial in which subjects are randomized to receive or not receive the drug,” he added.”Five years ago, it would’ve been unheard of to think that we could allow a child to die without getting a central line” for IV analgesics, Dr. DeBaun said. “But with the introduction of methadone into our pain management protocol, we are often able to get through their end of life care without placing a central line,” he added.(Source: J Pediatr 2003;142:000-000: Reuters Health: Anthony J. Brown, MD: May 6, 2003: Oncolink)