School of Medicine researchers have found that terminally ill children with cancer who have neuropathic pain require more opioids during the final days of life than those without neuropathic pain.
In addition, the team found preliminary evidence that a “cocktail” of several narcotics was significantly more effective at treating these patients than dramatically increasing the dosage of two commonly used opioids — morphine and benzodiazepine.
The study appears in the April issue of the Journal of Pediatrics.
“Our results indicate that health-care providers should anticipate large, rapid dosage increases of opioids when caring for children with neuropathic pain during the end of their life,” said study leader Michael DeBaun, M.D., assistant professor of pediatrics. “Conversely, patients without neuropathic pain often do not require such rapid dose increases and require attention to other comfort measures.”
Cancer patients with neuropathic pain — persistent pain caused by damage to the peripheral or central nervous system — describe the pain symptoms as similar to an electric shock, stabbing or burning. In addition, these patients often show signs of paralysis and pain hypersensitivity.
The World Health Organization guidelines for cancer-pain management rely on orally delivered opioids as the primary medication for controlling cancer-related pain. However, DeBaun said that approach fails to address the different causes of pain, which may require unique combinations of opioids and other narcotic agents.
In this retrospective study, DeBaun’s team compared the amount of morphine and benzodiazepine given to 18 children (12 of whom had neuropathic pain) in the last three days of life. The patients, ranging from 6 months to 19 years of age, were admitted between 1997 and 2000 to the BJC Pediatric Hospice program called “Wings.”
Researchers found that the children with neuropathic pain required more than 300 times the dose of morphine and benzodiazephine than patients without neuropathic pain.
Moreover, they determined that even these levels of pain treatment were inadequate for relieving pain.
Based on these findings, DeBaun and his colleagues gave three other terminally ill children with neuropathic pain another opioid drug called methadone to see if it would decrease the high levels of morphine and benzodiazephine needed for effective pain relief.
When methadone was used instead of increased doses of morphine and benzodiazephine, children required significantly lower doses of the other two drugs.
“Further research is required to determine the benefits of starting with methadone to relieve pain in children with neuropathic pain,” DeBaun said.