Novel botulinum compound relieves chronic pain

A modified form of botulinum toxin gives long-lasting pain relief in mice without adverse effects and, in time, could replace opioid drugs as a safe and effective way of treating chronic pain, according to research by UCL, the University of Sheffield and the Hospital for Sick Children, Toronto. For the study, published today in Science Translational Medicine and funded by the Medical Research Council, scientists deconstructed the botulinum molecule and reassembled it with an opioid called dermorphin to make Derm-BOT - a compound which successfully targets and silences pain signals from neurons in the spinal cords of mice. Key neurons in the spinal cord are targets for pain management as they directly 'sense' pain and send this information to the brain. "Injected into the spine, Derm-BOT relieves chronic pain - such as that caused by nerve damage - and avoids the adverse events of tolerance and addiction often associated with repeated opioid drug use," explained co-corresponding author, Professor Steve Hunt (UCL Cell & Developmental Biology). "It doesn't affect muscles like the botulinum toxin used to reduce wrinkles but it does block nerve pain for up to four months without affecting normal pain responses. It really could revolutionise how chronic pain is treated if we can translate it into clinic, removing the need for daily opioid intake." Chronic pain of 'moderate to severe' intensity is widespread affecting 7.8 million people in the UK and 19% of adult Europeans.