Opioids like morphine have now been shown to paradoxically cause an increase in chronic pain in lab rats, findings that could have far-reaching implications for humans.
Led by Assistant Research Professor Peter Grace and Distinguished Professor Linda Watkins, the study showed that just a few days of morphine treatment caused chronic pain that went on for several months by exacerbating the release of pain signals from specific immune cells in the spinal cord. The results suggest that the recent escalation of opioid prescriptions in humans may be a contributor to chronic pain.
“We are showing for the first time that even a brief exposure to opioids can have long-term negative effects on pain,” said Grace of the Department of Psychology and Neuroscience. “We found the treatment was contributing to the problem.”http://www.colorado.edu/news/features/narcotic-painkillers-prolong-pain-rats