Newly discovered painkiller could replace addictive opioids

Researchers from the University of Texas have discovered what they say is a powerful painkiller that acts on a previously unknown pain pathway.

The synthetic compound, known as UKH-1114, effectively relieves neuropathic pain in injured mice, but it works at a much lower dose, with a longer duration of action.

If the researchers can demonstrate that the drug is safe, effective and nonaddictive in humans – a process that can take years – the discovery could address one of today’s biggest public health challenges: the opioid crisis.

Opioids are addictive and users quickly develop a tolerance for the drugs, requiring them to increase the dose to achieve the same effect.

The study’s lead author, Stephen Martin, said: ‘This opens the door to having a new treatment for neuropathic pain that is not an opioid. And that has huge implications.’

The pain drug they found binds to a receptor on cells throughout the central nervous system called the sigma 2 receptor. Although it was discovered 25 years ago, scientists still did not know what sigma 2 did until now.

The researchers tested the new drug on mice with nerve damage and found that it alleviated pain as well as another drug (gabapentin) did, but at just one-sixth of the dose. It was effective for much longer, lasting for a couple of days, compared with between 4 and 6 hours. This research is the first to demonstrate that the sigma 2 receptor may be a target for treating neuropathic pain.

The study has been published in the journal ACS Chemical Neuroscience.