In a study released Wednesday morning, researchers from Duke University announced the discovery of a new class of pain relievers that targets two different—and relatively new—pain receptors. Published in Scientific Reports and funded by the National Institute of Health, the study is groundbreaking: a potential solution for a seemingly insurmountable problem.
According to the American Academy of Pain Medicine, chronic pain can be debilitating—incurring huge costs, disrupting sleep, and rendering daily activities unbearable. In the U.S. alone, an estimated 100 million people live with chronic pain—more than heart disease, diabetes, and cancer combined.
Despite rising concerns about their safety, opioids remain the first line of treatment for pain. In 2012 alone, doctors in the U.S. wrote 259 million prescriptions for painkillers, enough for every adult in the country to have their own bottle. While the drugs have shown to be effective in treating pain, they are extremely dangerous and addictive.
From 1999 to 2012, according to the director of the Centers for Disease Control and Prevention, the percentage of opioid deaths among women jumped a staggering 400 percent and 265 percent among men. Today NIH estimates that between 26.4 million and 36 million people nationwide abuse opiates.
Recent studies have even called into question whether the drugs could elicit the opposite response, by extending chronic pain. A study from the University of Colorado Boulder released this week found evidence that painkillers actually prolonged chronic pain in rats.
It’s with this backdrop that researchers from Duke set out to study a new class of drugs. The new class of painkillers targets two receptors known as TRPV4 and TRPA1, which according to the Duke researchers, “function in sensory nerve cells to directly sense painful stimuli.” The first is linked to joint pain, the second is described as a “promising target in pain and itch research.”
Initially seeking a more potent version of an earlier TRPV4 blocker, the researchers discovered that the new version also blocked TRPA1, making it a powerful dual-action pain reliever. One of the drugs, referred to as “16-8” proved successful at treating pain in mice including “abdominal aches” and “pancreas inflammation.”
Dr. Wolfgang Liedtke, a neurology professor and leader of the study, said the drug could be useful in treating many conditions. “As a physician, I soon realized the enormous potential that these compounds might have, given how beneficial dual-target molecules can be in clinical medicine,” he said.
A pain specialist, Liedtke suggested that the drug could be used to treat headaches, jaw pain, osteoarthritis, and nerve cell injuries. “We are very pleased with what is a first chapter in a highly promising story,” Liedtke said. “We hope to be able to develop these compounds for clinical use in humans or animals.”
If the medicine does prove successful in humans, it could be life-changing for the 100 million people currently suffering with chronic pain. As is, their current line of treatment may be making things better instead of worse—a sentiment that researchers from the CU-Boulder study on opioids prolonging pain captured perfectly in a statement.
“We are showing for the first time that even a brief exposure to opioids can have long-term negative effects on pain,” said Peter Grace, research assistant professor in behavioral neuroscience and psychology. “We found the treatment was contributing to the problem.”