A new study shows that people suffering nerve pain that doesn't respond to other treatments may get relief from levophanol, a morphine-like drug.
Neuropathic pain is the name given to persistent pain caused by nerve damage. It can be resistant to ordinary analgesics and sometimes antidepressants or anticonvulsants are used to treat it. Doctors have been reluctant to give opioids - strong painkillers like morphine - to those with neuropathic pain for fear of addiction, side effects and tolerance (needing increasing doses to get the same effect).

However, a new study from doctors at the University of California, San Francisco, now reveals that the opioid drug levomorphan is an effective treatment for neuropathic pain - at least for some patients. A group of 81 patients took either a high or a low dose of levomorphan. Some dropped out because of side effects, but in the high dose group, a fall of 36 per cent on the pain scale was noted. In the low strength group, pain went down by 21 per cent.

There were no problems with tolerance or addiction. Levomorphan seems to be most useful for patients with pain from multiple sclerosis, diabetic neuropathy and following shingles. It is not so effective for patients whose pain comes from some form of brain damage, like a stroke.