Anti-inflammatory Drugs Linked With Increased Risk Of Chronic Pain

Use of steroids and anti-inflammatory drugs for pain relief could raise the chances of developing chronic pain, new research from McGill University and colleagues in Italy suggests. The findings bring questions for conventional practices used to treat pain, of which chronic low back pain is the most commonly reported chronic pain condition.

For many decades it’s been standard medical practice to treat pain with anti-inflammatory drugs. But we found that this short-term fix could lead to longer-term problems,

said Jeffrey Mogil, a Professor in the Department of Psychology at McGill University and co-author of the study1.

Although little is understood of the molecular mechanisms behind the development of acute pain into chronic pain, evidence increasingly suggests2 that it is a complicated give and take involving the nervous and immune systems mediated by both neuronal and non-neuronal cells.

Neutrophil Activity

The study investigated the mechanisms of pain in both humans and mice. They found that neutrophils, a type of white blood cell that helps the body fight infection, play an important role in alleviating pain.

In analyzing the genes of people suffering from lower back pain, we observed active changes in genes over time in people whose pain went away. Changes in the blood cells and their activity seemed to be the most important factor, especially in cells called neutrophils,

said Professor Luda Diatchenko, Canada Excellence Research Chair in Human Pain Genetics.

Experimentally blocking neutrophils in mice prolonged the pain up to ten times the normal duration. Treating the pain with anti-inflammatory drugs and steroids like dexamethasone and diclofenac also produced the same result, although they were effective against pain early on.

Time To Reconsider Anti-inflammatories

The findings are also supported by a separate analysis of data involving 500,000 people from the UK Biobank project that showed that those taking anti-inflammatory drugs to treat their pain were more likely to have pain two to ten years later, an effect not seen in people taking acetaminophen or anti-depressants.

Our findings suggest it may be time to reconsider the way we treat acute pain. Luckily pain can be killed in other ways that don’t involve interfering with inflammation,

said Massimo Allegri, a Physician at the Policlinico of Monza Hospital in Italy and Ensemble Hospitalier de la Cote in Switzerland.

The findings need to be followed up with clinical trials that directly compare anti-inflammatory drugs to other pain killers that relieve aches and pains but don’t disrupt inflammation.

  1. Marc Parisien et al Acute inflammatory response via neutrophil activation protects against the development of chronic pain Science Translational Medicine Vol. 14, No. 644, DOI: 10.1126/scitranslmed.abj9954 ↩︎
  2. R.-R. Ji, A. Chamessian, Y.-Q. Zhang Pain regulation by non-neuronal cells and inflammation Science 354, 572–577 (2016). ↩︎