Australian Study Suggests Some Painkillers Don’t Work for Back Pain

By  //  October 18, 2023

A study by Australian researchers indicates opioids may not be more effective in alleviating low back pain than placebos.

The randomized placebo-controlled trial involved over 340 patients with moderate low back or neck pain in healthcare sites in Sydney. The team of Australian researchers conducted the study of primary care or emergency department patients. The results indicate that those who received opioids vs. sugar pills reported no difference in pain severity after six weeks.

While the researchers conducted the study in Australia, the results may apply to anyone suffering from nonspecific, acute back pain. Lower back pain affected over 600 million adults globally in 2020, driving them to seek relief through various means. Most people would try over-the-counter treatments such as anti-inflammatories or gifts for back pain relief, like heating pads. When those remedies don’t work,  doctors may prescribe a course of opioids to alleviate short-term but acute pain.

However, the study suggests opioids may not be effective in easing acute lower back or neck pain. The results surprised the researchers, including Sydney Pharmacy School dean of Pharmacy Andrew McLachlan. He states that he expected a difference between opioids and placebos, which didn’t happen.

Additionally, the trial indicated that people who got opioids tended to misuse them 12 months after for pain relief. It highlighted the risk of abuse of opioids for pain relief.

Previous research focused on chronic pain treatment with opioids, showing that long-term use may be counterproductive. The newest research suggests that, at least for acute pain not lasting more than three months, opioids don’t help at all.

Experts believe the study may significantly affect guidelines on back pain treatment. That includes the University of Michigan director of research on opioids and pain, Dr. Mark Bicket.

Others worry that the results could get the wrong idea about opioids and their broad effect on acute pain. The study involves a small cohort of patients, so generalizing may be premature. It may lead to the denial of care for people with other types of pain, such as post-surgical pain. Opioids may be effective in providing relief in such situations.

No Statistical Difference From Placebos

The clinical trial outcomes highlight the gap in our knowledge of the effectiveness of opioids on acute back pain. Researchers recruited patients suffering from acute back or neck pain beginning 12 weeks or sooner from over 150 healthcare facilities. They assigned them to opioid and placebo groups and completed the study over six years.

Excluded from the study were patients with fractures, illnesses, surgery, and any spinal pathology causing the pain. Participants suffered from acute-onset pain resulting from sleeping position, twisting awkwardly, and other nonspecific causes not diagnosable through X-rays.

Researchers did not inform the patients whether they received a placebo or opioid. The placebo group received sugar pills, while the opioid group received a combination of naloxone and oxycodone. The combination minimized gastrointestinal side effects associated with opioids to prevent patients from realizing they are in that group.

Some people know that naloxone counteracts the effects of opioids when given nasally or intravenously, mainly to treat overdoses. However, it doesn’t have the same impact when orally taken as it doesn’t enter the bloodstream.

After six weeks of treatment, the two groups reported no significant variation in their pain scores. The trend persisted after 12 weeks.

The researchers focused primarily on pain scores after six weeks, increasing the doses at that point gradually. The dosage reached the optimal level of 20 milligrams of oxycodone daily. The results indicate that opioids did not relieve pain in detectable amounts for moderate to severe lower back pain. They contradicted the results of prior research on chronic pain over a longer time.

Additionally, follow-up after 12 months showed risky behavior in 20 percent of the opioid group. Interestingly, 10 percent of those in the placebo group displayed the same tendency toward misuse.

Controversial Findings

Given the recent lawsuits against Purdue Pharma, medical experts will likely cite the Australian study to support debates against opioid use. Plaintiffs involved in the product liability cases held the company and the Sacklers accountable for promoting the opioid crisis. U.S. guidelines already advise caution when using opioids for treating acute pain, recommending them only as a last resort.

While the study has limitations, many believe it yielded valid results, highlighting gaps in understanding opioid effects. It will likely stir up controversy in prescribing the drug category in alleviating back pain.

The only question on the minds of medical professionals is why researchers had not undertaken such a trial sooner. The body of research on opioids is extensive, so perhaps researchers believed they already knew the answers. However, previous studies failed to ask fundamental questions like the Australian study did.

However, applying its results to a broad spectrum of acute pain treatment would be unwise. Given the small population of the trial, further research is necessary to confirm the results before modifying existing guidelines. Making premature changes in opioid prescription regulations could negatively impact the care of many people.

It all boils down to a risk-benefit analysis. Suppose the Australian clinical trial findings are valid and opioids cannot significantly help people with nonspecific, acute-onset back pain. The attendant risks of opioid misuse, no matter how slight, would not be worth it.

What’s next?

The bottom line is that the trial opens a line of research that the scientific community must pursue further. Despite being well-designed, the trial results do not necessarily hold true for acute pain management as a whole.  

Some believe using oxycodone, a long-acting opioid, may not have been the best choice for treating acute pain. The goal of giving patients with nonspecific acute pain is to provide quick relief when needed, which oxycodone does not. Using short-acting opioids designed for patients to take as needed may have yielded different results.

The researchers also restricted the trial population to patients with nonspecific back and neck pain that had recently started. These types of pain tend to be due to musculoskeletal problems, so the results do not apply to other pain classifications.

Researchers’ main concern is determining the benefits of extended use of opioids versus the risks. The results are not definitive, but they suggest the value of non-opioid options for low back pain treatment.