The researchers also replicated the findings in mice, either by compressing the animals’ sciatic nerves to produce back and leg pain, or by injecting an irritant into the sciatic nerves. When they blocked the animals’ immune response with dexamethasone, a steroid commonly used to treat back pain, the pain became chronic.
Six tips for treating chronic pain
The group then asked whether chronic pain resulted from pain suppression or inflammation suppression. So they gave some mice a prescription anti-inflammatory, diclofenac. Other mice were given one of three other pain relievers or pain relievers – gabapentin, morphine and lidocaine.
Only with diclofenac did the pain persist, becoming chronic.
These results led them to ask: were patients who took nonsteroidal anti-inflammatory drugs like ibuprofen or steroids like dexamethasone to relieve back pain also more likely to develop chronic pain?
The researchers turned to data from the UK Biobank, a repository of information about the medical conditions and drug use of half a million patients. They studied 2,163 people with acute back pain, 461 of whom went on to have chronic pain. Those who took a nonsteroidal anti-inflammatory drug were nearly twice as likely to develop chronic back pain as those who took other drugs or no drugs at all, the researchers found.
Dr. Diatchenko said she doesn’t believe her findings have anything to do with the issue of opioid addiction. In fact, she said, “to avoid opioids, doctors started prescribing more NSAIDs.”
“We need to think more about how to treat our patients,” she said.
The trend towards the use of non-steroidal anti-inflammatory drugs persists despite their inexpressive performance. An analysis of randomized controlled trials found that these drugs had almost no benefit over placebos in reducing low back pain.
Dr. Atlas says short-term use of nonsteroidal anti-inflammatory drugs is likely not harmful, but the new study, he adds, while it doesn’t prove long-term use is harmful, “at least provides a biological mechanism that says the short term use is not the same as long term use.”