Mar 05, 2002
Morphine therapy controls some aspects of central pain syndromes, but only a minority of patients seem to tolerate long-term therapy, according to a report published in the February 26th issue of Neurology.
Dr. Didier Bouhassira, from Hopital Ambroise Pare in Boulogne, France, and colleagues performed a randomized, placebo-controlled study to assess the benefits of morphine in 15 patients with central pain syndromes. Six patients had experienced a prior stroke and nine had spinal cord injuries. After being treated with IV morphine, the patients were started on sustained oral morphine.
Treatment with morphine was associated with a significant improvement in dynamic mechanical allodynia, but had no effect on other evoked pains, the researchers note. Seven patients reported improvements in spontaneous pain with morphine, but, overall, no treatment effect was observed.
The reduction in spontaneous pain that occurred in some patients was directly related to a decrease in heat sensitivity on the nonpainful contralateral side, the investigators state. This finding suggests that the general nociceptive activity of morphine was responsible for the reductions in spontaneous pain.
Only three patients remained on oral morphine for more than 1 year, the authors point out. The emergence of side effects appeared to be a major reason for treatment discontinuation.
"Opioids may represent a therapeutic alternative for central neuropathic pains, but only a small group of patients seem to be able to continue long-term treatment, because of an unfavorable balance between efficacy and side effects," Dr. Bouhassira's team concludes.
© 2002 Reuters Ltd