An international team of researchers are looking at ways to develop non-narcotic treatments to deal with chronic pain. The team, which is led by Boston Children’s Hospital, have found a way to stop the cycle of pain hypersensitivity without the use of addictive drugs.
It’s hoped that this research, which was recently published in the journal Neuron, will lead to treatments for sufferers of the kind of chronic pain which is caused by damage to the nerves. At the moment, treatments only offer meaningful pain relief for about 15 percent of sufferers.
Human genetics used to guide the research
Despite performing well in animal trials, most pain medications that have been tested in the last ten years have failed to offer significant relief during human trials. In this latest study, human genetics have been used to guide the research right from the start. Using information gained from previous studies which showed that people who have variants of a particular gene are at a markedly lower risk for chronic pain, the researchers were able to replicate this gene variant. Using reverse engineering, the team of scientists, led by Clifford Woolf and Michael Costigan, modelled this in mice. Their findings showed that mice with severed sensory nerves began to produce an excess of a substance called BH4, and that they had increased pain sensitivity even when they weren’t injured. Other mice that were genetically unable to produce BH4 showed less pain sensitivity after nerve injuries. This suggested that the presence of BH4 is sufficient to produce pain.
The scientists were able to target the enzyme which produces BH4
Using this information the researchers were able to block the production of BH4 with a drug that was specifically designed to target the enzyme which produces BH4. This meant that they were able to reduce the pain caused by the injury to the nerve, without affecting the protection pain sensation we feel that helps us to avoid injury.
The researchers now need to fine-tune this treatment. As BH4 is active throughout the body, its production needs to be controlled without being eliminated entirely. So far, the researchers have been able to reduce BH4 production without causing any neural or cardiovascular side effects, suggesting that this is a viable approach to reducing pain hypersensitivity.