Got back pain? You should rethink reaching for the opioid-based painkillers

We know the feeling: when back pain strikes. Photo: shutterstock.com
We know the feeling: when back pain strikes. Photo: shutterstock.com

Got back pain? Think once, twice and then again before taking any opioid-based painkillers, warn international experts after the release of groundbreaking new research.

It found opioids were no better than ibuprofen or paracetamol at reducing lower back pain over a 12-month period, yet these opioids came with the threat of dependence and addiction, which has been blamed for an increase in accidental overdoses.

A long-term trial by Erin Krebs and the Minneapolis Veterans Health Care System studied 240 veterans taking opioids for chronic back and knee pain compared with those treated by non-opioids. The results were presented at a major medical conference in the US, but are yet to be published.

"The data do not support opioids' reputation as 'powerful painkillers'," Dr Krebs told the medical publicationThe Back Letter.

"The results support CDC [Centres for Disease Control and Prevention] guideline recommendation: that non-opioid medications are preferred for chronic pain."

They were also consistent with shorter studies that founds opioids to be no more effective than other groups of analgesics for lower back pain than anti-inflammatories or antidepressants, according to the Cochrane Review.

Back pain researcher James McAuley at Sydney's Neuroscience Research Australia (NeuRA) said Kreb's research was "important" and relevant to the almost 20 per cent of Australians with low back pain who were prescribed opioids,

Experts are looking for other ways to treat pain to reverse the explosion in the use of opioids, particularly to treat chronic pain. About 3 million Australians take opioids every year.

While exercise was recommended for most people with chronic back pain, it didn't lessen the pain, Dr McAuley said.

Now new research projects at NeuRA have found that changing the way that the brain deals with pain can make a big difference. These interventions, dubbed pain neuroscience, could also work to reduce other chronic pain. "The reason you have pain is that your brain has looked at all the evidence from your senses that there is danger to a certain part of your body. And if there is a threat, your brain produces pain so that you do something to remove the danger," Dr McAuley said.

Research by Dr McAuley and his colleague Sylvia Gustin found that the brains of people with chronic pain changed, with the areas that control emotions, such as the medial prefrontal cortex and the anterior insula, shrinking. "These brain changes increase the longer that someone has pain, but recently they have been shown to return to normal if pain goes away," he said.

They also found that people with acute back pain lack a chemical called Gaba, which calms the neurons in the brain. Gaba - gamma-Aminobutyric acid - reduces neuronal excitability throughout the nervous system.

To stop someone with back pain developing chronic problems, a pilot study at NeuRA by Dr McAuley and Dr Gustin found the use of a hypnotic used to help people sleep increased the Gaba.

They will soon launch a large randomised study in the hope this will prevent acute pain from becoming chronic.

It was the puzzle of phantom pain that prompted the new field of brain neuroscience, Dr McAuley said.

Another promising new study tried to turn down the "pain alarm" in people with chronic pain. In these cases, the brain's ability to locate the source of the pain had become inaccurate.

"If I was to touch you on the back, you couldn't tell whether I was touching you with a cotton wool bud or something sharp," he said of people with this kind of chronic pain.

By touching the backs of these people - and retraining the brain to identify different sensations - the brain's pain alarm was switched off, and sensitivity returned to individual areas, leading to less pain.Dr McAuley also recommended against back X-rays for anything other than very serious back pain. They only increased anxiety.

As for the American study, Stanford University Professor of Medicine Steven Asch responded by immediately tweeting: "Long-term opioids no better than Motrin for low back pain at 12 months. Just don't start them."

Asked if he had any advice for patients and physicians in the wake of this study, Asch told The Back Letter to use caution.

"Think twice before starting opiates in chronic musculoskeletal pain, then think again. They will work for a while, but this study says they don't do any better than Motrin or other [non-opioid drug] therapies in the long run."

He told The Back Letter that the study on opioids versus non-opioid treatment of back pain filled "a gaping hole in the literature". "Many have asked, 'Do opioids work for chronic musculoskeletal pain?' but until now, there have been few, if any, high-quality trials," he said.

"Now we know better. The best evidence argues against the use of chronic opiates for patients with long-term back or other musculoskeletal pain."

This story Got back pain? You should rethink reaching for the opioid-based painkillers first appeared on The Sydney Morning Herald.