By Pat Anson, Editor
Researchers at The University of Texas have discovered a potent non-opioid pain reliever that acts on a previously unknown pain pathway. They say the synthetic compound, known as UKH-1114, is as effective at relieving neuropathic pain in laboratory mice as gabapentin, but lasts much longer.
Now scientists need to find out if drug is safe, effective and nonaddictive in humans -- a process that could take years.
"This opens the door to having a new treatment for neuropathic pain that is not an opioid," said Stephen Martin, a chemistry professor at The University of Texas at Austin. "And that has huge implications."
UKH-1114 binds to a receptor on cells in the central nervous system called the sigma 2 receptor. Although it was discovered 25 years ago, scientists did not know what sigma 2 did until now.
Theodore Price, an associate professor of neuroscience at The University of Texas at Dallas, tested UKH-1114 on mice with nerve damage and found that it alleviated pain as well as gabapentin did, but was effective much longer -- lasting for a couple of days, compared to 4 to 6 hours. Price’s research was the first to demonstrate that the sigma 2 receptor may be a target for treating neuropathic pain.
"We started out just working on fundamental chemistry in the lab," said James Sahn, a research scientist at The University of Texas at Austin. "But now we see the possibility that our discoveries could improve the quality of people's lives. That is very satisfying."
Sahn and his colleagues have filed patent applications on the new compound. Their findings have been published in the journal ACS Chemical Neuroscience. An earlier paper on the sigma 2 receptor was published in the journal Proceedings of the National Academy of Sciences.
Chronic neuropathic pain is caused when nerves in the central nervous system are damaged by chemotherapy, shingles, diabetes or injuries to the brain or spinal cord. About 8% of adults worldwide suffer from some form of neuropathy.
Diabetic peripheral neuropathy causes nerves to send out abnormal signals. Patients can feel stinging or burning pain, as well as loss of feeling, in their toes, feet, legs, hands and arms. Nearly 26 million Americans have diabetes and about half have neuropathy, according to the American Diabetes Association.
Many patients say drugs commonly used to treat neuropathic pain, such as gabapentin (Neurontin) and pregabalin (Lyrica), either don’t work or have unpleasant side effects such as dizziness, fatigue and diminished cognitive ability. Some doctors also feel the drugs are being overprescribed as alternatives to opioid pain medication.