Summary: Anti-inflammatories can relieve pain in the short term, but blocking inflammation can lead to longer chronic pain, a new study reports.
Source: McGill University
The use of anti-inflammatory medications and steroids to relieve pain can increase the chance of developing chronic pain, according to researchers from McGill University and colleagues in Italy.
Their research raises the question of common practices used to relieve pain. Normal recovery from a painful injury includes inflammation and obstruction that inflammation medications can lead to more difficult to treat pain.
“For decades, it has been common medical practice to treat pain with anti-inflammatory medications. But we have found that this short-term cure can lead to longer-term problems,” said Jeffrey Mogil. , a Professor in the Department of Psychology at McGill University and EP Taylor Chair of Pain Studies.
The difference between people who are better and who are not
In the study published in Science Translational Medicine, the researchers examined the mechanisms of pain in humans and mice. They found that neutrophils — a type of white blood cell that helps the body fight infection — play an important role in resolving pain.
“In analyzing the genes in people suffering from low back pain, we observed active gene changes over time in people whose pain disappeared. The changes in blood cells and their activity seems to be the most important factor, especially in cells called neutrophils, ”said Luda Diatchenko who is a Professor in the Faculty of Medicine, Faculty of Dentistry, and Canada Excellence Research Chair in Human Pain Genetics.
Inflammation plays an important role in pain resolution
“Neutrophils dominate the early stages of inflammation and set the stage for the healing of tissue damage. Inflammation occurs for a reason, and it seems dangerous to interfere with it,” said Professor Mogil, who is also a member of Alan Edwards Center for Research on Pain with Professor Diatchenko.
Experimental blockade of neutrophils in mice prolongs pain up to ten times the normal duration. Treating pain with anti-inflammatory drugs and steroids such as dexamethasone and diclofenac also produces the same result, even if it is effective against pain earlier.
These findings are also supported by a separate analysis of 500,000 people in the United Kingdom which showed that those taking anti-inflammatory medications to treat their pain were more likely to have pain two to ten. years ago, an effect not seen in people taking acetaminophen or antidepressants.
Reconsider standard medical treatment of acute pain
“Our findings suggest that it may be time to rethink the way we treat severe pain. Luckily the pain can be killed in other ways unrelated to inflammatory intervention,” he said. as Massimo Allegri, a Policlinico Doctor at Monza Hospital in Italy and Ensemble Hospitalier de la Cote in Switzerland.
“We discovered that pain management is actually an active biological process,” Professor Diatchenko said. These findings should be followed by clinical trials directly comparing anti-inflammatory medications with other painkillers that can relieve aches and pains but do not interfere with inflammation.
“Acute inflammatory response by neutrophil activation protects against the progression of chronic pain” by Marc Parisien et al. published in Science Translational Medicine.
About this disease research news
Original Research: Open access.
“Acute inflammatory response by neutrophil activation protects against the development of chronic pain”By Marc Parisien et al. Science Translational Medicine
Acute inflammatory response by neutrophil activation protects against the development of chronic pain
The transition from acute to chronic pain is very important but not very well understood.
Here, we examined the pathophysiological mechanisms underlying the transition from acute to chronic low back pain (LBP) and performed a transcriptome-wide analysis of peripheral immune cells in 98 participants with acute LBP, followed by 3 months.
Transcriptomic changes were compared between patients whose LBP resolved at 3 months with those whose LBP persisted. We found thousands of dynamic transcription changes over 3 months in LBP participants with resolved pain but none in those with persistent pain.
Transient neutrophil-driven up-regulation of inflammatory responses protects against the transition to chronic pain. In mouse pain trials, early treatment with a steroid or nonsteroidal anti-inflammatory drug (NSAID) also brought about chronic pain although analgesic in the short term; Such prolongation has not been observed with other analgesics.
Depletion of neutrophils delayed pain resolution in mice, while peripheral injection of the neutrophils themselves, or the S100A8/A9 proteins normally released by neutrophils, inhibited the progression of chronic pain induced by an anti-inflammatory drug.
Analysis of the pain trajectories of human subjects reporting acute back pain by UK Biobank indicated a high risk of pain progression for subjects taking NSAIDs.
Thus, despite analgesic efficacy at early time points, management of acute inflammation may be counterproductive for long-term outcome in LBP patients.