Anti-inflammatories, paradoxically, although effective against acute pain, can trigger chronic pain. Here’s how.
It may sound silly, but the anti-inflammatories we commonly use to fight pain can increase the risk of chronic pain. In other words, ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs) that are short-term pain relievers can have a negative effect on long-term pain. The reason is that they interfere with the inflammatory process that occurs naturally when you feel pain for any reason (like an injury); blocking it would only produce pain that lasts longer and is harder to deal with. For this reason, scientists suggest reconsidering the way we deal with pain, switching to painkillers but not anti-inflammatories.
To discover that anti-inflammatories may increase the risk of chronic pain, an international research team led by Canadian scientists from the Alan Edwards Center for Pain Research at McGill University in Montreal, who collaborated with colleagues from the Department of Medicine and Surgery of the University of Parma, the Department of Anaesthesiology, Pain and Palliative Medicine of Radboud University of Nijmegen (Netherlands), the University of North Carolina, the Polyclinic of Monza and other institutes. The scientists, coordinated by Professor Luda Diatchenko, a lecturer at the Faculty of Dentistry and Oral Health Sciences of the Canadian University, reached their conclusions after analyzing in depth the mechanisms of pain in patients and in murine models (mice).
First, Professor Diatchenko and his colleagues focused on neutrophil granulocytes, a type of white blood cell that specializes in protecting the body against infection but also plays a fundamental role in pain. By analyzing gene activity in people who used anti-inflammatories for low back pain, they found that neutrophil-related genes were up-regulated in those who had recovered from pain, whereas they were not in those who had persistent pain at the end of treatment (three months). The same situation has been seen in people with temporomandibular disorders, which cause pain in muscles associated with the jaw and ears. “Neutrophils dominate the early stages of inflammation and set the stage for the repair of tissue damage. Inflammation happens for a reason and it seems dangerous to intervene in it,” study co-author Professor Jeffrey S. Mogil said in a press release.
In the next phase of the research, the scientists involved the mice, subjecting them to various experiments. In those with blocked neutrophils, for example, chronic pain was prolonged up to ten times, while in those treated with anti-inflammatories the pain lasted more than twice as long as in those untreated. On the other hand, the peripheral injection of neutrophils and S100A8/A9 proteins which are normally produced by neutrophils, for its part, avoided the prolongation of pain due to the use of an anti-inflammatory. Moreover, by analyzing data from more than 500,000 patients from the UK Biobank, scientists observed that people who treated acute pain with anti-inflammatories were more likely to suffer from chronic pain for 2 to 10 years than those who treated acute pain with anti-inflammatories. who used other analgesics. In summary, all of these results show that interfering with the natural neutrophil-triggered inflammatory process through the use of anti-inflammatories (such as NSAIDs) can have a positive short-term effect on pain, but there is a risk of triggering it. chronic.
“Our results suggest that it may be time to reconsider how we treat acute pain. Fortunately, the pain can be stopped by other means that do not involve interference with the inflammation,” said Professor Massimo Allegri from the Monza Polyclinic. “These results should be followed by clinical trials directly comparing anti-inflammatories with other analgesics that relieve pain but do not stop inflammation,” echoed Professor Diatchenko. Details of the research “Acute inflammatory response via neutrophil activation protects against the development of chronic pain” have been published in the scientific journal Science Translational Medicine.