A study released on Monday by the researchers at the University College London (UCL) using transgenic mice, have discovered how to replicate the painlessness experienced by people with rare mutations.

Professor John Wood

Prof. John Wood, one of the authors of the research paper, said that the findings could lead to the development of next-generation painkillers.

“People born with a rare genetic mutation are unable to feel pain.

`This is connected to certain mechanism in the nervous system.

“There are “channels” that allow messages to pass along nerve cell membranes, and they are vital for electrical signalling in the nervous system,’’ he said.

Wood said that previous study has shown that sodium channel Nav1.7, was particularly important for signalling in pain pathways and people born with non-functioning Nav1.7 do not feel pain.

“Drugs that block Nav1.7 have since been developed but they had disappointingly weak effects.

He said that the new study, published in the journal Nature Communications, revealed that mice and people who lack Nav1.7 also produce higher than normal levels of natural opioid peptides.

“To examine if opioids were important for painlessness, the researchers gave naloxone, an opioid blocker, to mice lacking Nav1.7 and found that they became able to feel pain.

“They then gave naloxone to a 39-year-old woman with the rare mutation and she felt pain for the first time in her life,’’ he said.

Wood noted that the secret ingredient turned out to be good old-fashioned opioid peptides, and we have now filed a patent for combining low dose opioids with Nav1.7 blockers.

“This will replicate the painlessness experienced by people with rare mutations, and we have already successfully tested this approach in unmodified mice.

Wood said that people with non-functioning Nav1.7 produce low levels of opioids throughout their lives without developing tolerance or experiencing unpleasant side-effects.

He expressed the hope to see the findings tested in human trials by 2017.

Wood said that with this done he and his team could then start looking into drug combinations to help the millions of chronic pain patients around the world.