The use of non-steroidal anti-inflammatory analgesics, such as Advil or Motrin, which are commonly used to treat severe pain such as back pain, will increase the risk of developing chronic pain, researchers in Quebec have discovered.
This observation is a result of chance. Bioinformatician Marc Parisien and his colleagues at McGill University were trying to better understand the mechanisms involved in disease onset when they made a discovery that seemed to shake up the traditional concept of acute pain treatment.
The Montreal team followed 98 people who attended a pain management clinic to treat severe back pain. He took blood samples from these patients at their first appointments and then three months later, with the goal of comparing their genetic information. The goal of the researchers was to compare data from those who resolved lower back pain to patients whose pain had become chronic.
” It’s a bit like taking inventory of what’s going on in their blood over time. What would be the difference between people who heal quickly and people who experience it? “
The findings of the researcher and his colleagues were surprising. All tests lead us to neutrophils, said Mr. Parisien. Neutrophils are white blood cells that are involved in the body’s defense against bacterial infections, but they are also present in the early stages of acute inflammation.
” Changes in gene expression were observed in subjects whose disease disappeared between two appointments, indicating that neutrophils also play an important role in disease resolution. “
Rapid regulation of inflammatory responses of neutrophils appears to protect against the development of chronic disease.continued the researcher.
Experiments on rats
This discovery led the team to alter neutrophil levels in groups of mice that underwent the same surgery to test the effects of these cells on disease control.
These experiments showed that blocking the action of neutrophils prolongs the time by up to ten times the pain felt by rats.
One group of rats received early treatment using nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief. The soothing effects of anti-inflammatories have been observed in intense postoperative pain. So these drugs protect against the disease, but the suffering is prolonged over timesaid Marc Parisien.
This finding was not seen with other pain relievers such as acetaminophen (Tylenol) or opioids (codeine, morphine, and oxycodone).
” You still need to be careful, because while rats have immune systems similar to humans, they are not identical. And humans have more neutrophils in their blood than rats. “
Back to the people
Using these results obtained in rats, the McGill team returned to verify their results with a larger number of people. He conducted an analysis of the records of 500,000 people participating in the UK Biobank, a biomedical and genetic database developed over 20 years in the United Kingdom.
This review shows that participants taking NSAIDs for pain are more likely to experience chronic pain after two to ten years.
Again, this effect is not seen in people taking acetaminophen or other pain relievers.
For Dr. Anne-Marie Pinard, chronic pain anesthesiologist and professor at Université Laval, all of these results are very interesting, even if they remain in the field of basic research today.
” The idea that blocking inflammation can interfere with healing isn’t entirely new, but how they brought it up with such solid evidence is interesting. “
Dr. believes. This pinard is necessary modulate these results. What the patient bank study shows is an association. We are not taught in a clear, distinct and precise way in a cause and effect relationship.
Marc Parisien and his colleagues recognize the limitations of their work.
” Our evidence remains circumstantial. Ideally, this should be verified in other cohorts, for example in the Quebec CARTaGENE database and through randomized double-blind clinical trials. “
The authors therefore acknowledge that other work must be undertaken to confirm their findings, questioning, more or less, traditional pain relief treatments.
The trade-off between treatment of acute pain versus chronic pain should be assessedexplained Mr. Parisien, who added that sometimes short-term repairs can cause long-term problems.
An inflammatory debate
The publication of this work has created a little excitement in the world of disease treatment.
This study is extremely interesting because it opens the way to meditation, especially for health professionals.said Pre Pinard.
” We often think that really no one should be hurt in life. I’m not saying you have to endure severe pain, but severe pain is a useful signal from the body to relax, not to step on your foot or dance when your back hurts. […] The body does things right when you let it go, it creates an inflammatory response to heal. “
Now, do we have to throw anti-inflammatories in the trash? No. It shows us, however, that inflammation is necessary for the healing process.he added.
Create new drugs
Mr. Parisien came up with the idea of salvage to improve or develop new drugs to counter the ill effects of NSAIDs current.
” We can maintain the intense pain-reducing effect of anti-inflammatories by obscuring the pain-prolonging effect using a protein complex. “
To this end, the study also established that injection of a complex of proteins (S100A8/A9) normally released by neutrophils prevented the development of chronic pain caused by an anti-inflammatory drug.
Details of this work were published in the journal Science Translational Medicine (New window) (in English).
Source: Radio-Canada
