A study published recently in the Proceedings of the National Academy of Sciences claims to document the phenomenon known as opioid-induced hyperalgesia, a belief that opioid therapy for chronic pain may actually make that pain worse. The research on rats was conducted at the University of Colorado, Boulder and concluded that morphine treatment of induced nerve injury intensified the release of pain signals from specific immune cells in the rats’ spinal cord, making the pain worse. The effect was noted after as few as 5 days of opioid treatment, and persisted for several months. Lead author Peter Grace, PhD, Research Assistant Professor, psychology and neuroscience commented, “We are showing for the first time that even a brief exposure to opioids can have long-term negative effects on pain.” The journal article abstract concludes, “This study predicts that prolonged pain is an unrealized and clinically concerning consequence of the abundant use of opioids in chronic pain.”
But in commentary posted on the Health News Review website, Stephen Martin, MD, EdM, Associate Professor of Family Medicine and Community Health at the University of Massachusetts Medical School, cautions against extrapolation and generalization of the findings with respect to opioid therapy in human patients. Dr Martin writes: “A rat study headlined ‘Narcotic painkillers cause chronic pain’ – that doesn’t mention the rat subjects – is the latest example of the pendulum being pulled back so far it is straining credulity as well as contributing to people’s suffering.” In concert with many PAINWeek faculty contributors, Dr. Martin advises practitioners to follow universal precautions in prescribing opioids, to work to find the best individual approach to mitigating patients’ pain, to be mindful of side effects and “untoward outcomes” and to practice with compassion.
Read more about hyperalgesia on painweek.org here.
Read the post from Dr. Martin in Health News Review here.
The study abstract may be read here.