Snippet from the article:
Although medicine has advanced far enough to treat basic headaches, strained muscles and the agony of having a cavity filled, inflammatory painâ€”the kind that results from osteoarthritis, bone cancer and back injuriesâ€”has proved to be a far more elusive target. Current remedies, including morphine and other opiates, flood all the nerves of the body, causing dangerous side effects. More localized remedies, such as steroid injections, wear off over time. Recently researchers have begun working with a toxin found in a Moroccan cactuslike plant that may be able to deliver permanent, local pain relief with a single injection.
The compound, called resiniferatoxin (RTX), works by destroying the neurons specifically responsible for inflammatory pain. These neurons extend from the body’s periphery (including the skin and internal organs) to the spinal cord, carrying pain signals along their axons. The signals eventually travel up to the brain.
Read the rest at Scientific American — Prickly Painkiller
This toxin specifically kills only those neurons that produce a specific protein that transmits the “sensation of noxious heat and inflammation“, while leaving other nerves alone. We have known for many years that a single nerve carries many sensations, pain being one of them. We use this in our local anesthetics, where we can block pain, but not sensation.
Considering that pain accounts for many of the visits to doctor’s offices, such a treatment sounds miraculous; however, pain can be our friend as well. Using acute pain prevents us from doing things that could harm us, like running on a leg that has a crack or a fracture present.
The article concludes with a quote from David Maine, director of the Center for Interventional Pain Medicine at Mercy Medical Center in Baltimore: “When you can streamline where a drug acts and avoid consequences outside of that, you potentially have a winner.”