°µÍø½ûÇø

Researchers looked specifically at neck and lower back pain because "it's a very, very prevalent condition" and opioids are frequently prescribed to relieve it, said senior author Christine Lin, a professor at the institute for musculoskeletal health at the University of Sydney.

The randomized control trial recruited 347 participants who had been experiencing at least moderate pain for 12 weeks or less. About half of the participants (174) were given oxycodone-naloxone daily and 172 were given placebo pills. One participant left the trial due to illness.

The participants didn't know whether they were receiving opioid medication or a placebo.

The trial doctors were instructed to give all patients "guideline-recommended care," including reassuring patients that their pain would get better with time and encouraging them to stay active and avoid bed rest.

Some patients in both groups also received non-opioid medication such as non-steroidal anti-inflammatory drugs (NSAIDs). Common examples of NSAIDs are ibuprofen, Aspirin or naproxen sodium.

After six weeks, the researchers asked participants about the severity of their pain, rating it on a scale of one to 10, with 10 being the highest level of pain. The average pain score for those given opioids was 2.78, compared to 2.25 in the placebo group.

The Australian study is "good" and most participants were likely suffering from muscular pain, given that people with serious spinal issues were excluded, said Dr. Hance Clarke, medical director of the pain research unit at University Health Network in Toronto, who was not involved in the study.

The findings reflect the way muscular pain in the neck and lower back is increasingly treated in Canada, said Clarke, who is also president-elect of the Canadian Pain Society.

"The impetus for all of these types of randomized controlled trials looking at opioids and their response in specific patient populations is a direct response to the opioid crisis and how do we improve prescribing habits and how do we keep people safe," Clarke said.

"There's very little role for opioids in an acute muscle pain-type condition and I don't think there's going to be a lot of debate about this," he said.

Both Clarke and Lin noted that most acute muscle injuries tend to get better over time.

But opioids are still needed for short-term relief of other types of severe pain, such as right after surgery and with broken bones, Clarke emphasized.

"An acute muscle injury is completely different to a fractured femur," he said.

When opioids are used in those cases, it's important to take them for the shortest time possible to avoid longer-term consequences, Lin said.

"It's not just addiction," she said. "People develop tolerance to opioids. So over time you need more and more medicines in order to get the same level of pain relief."

People who take opioids also often suffer from constipation and nausea, Lin said.

In addition, previous research has shown that after a few days, opioids aren't any more effective than other pain relief measures, she said.

Clarke noted that end-of-life care is another instance where opioids are often necessary.

Although the study shows opioids are not effective in treating muscular neck and lower back pain, anyone currently taking them should not suddenly stop, but should seek help from their doctor or other health-care professionals to avoid withdrawal effects, Lin cautioned.

The study took place across 157 sites in Australia between 2016 and 2021.

Limitations of the study included many participants not taking their pills as directed. However, the researchers noted that the rate of compliance didn't differ between the opioid and placebo groups and that the rate was consistent with other drug trials involving back pain.

This report by °µÍø½ûÇø was first published June 30, 2023.

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.