Study finds that opioids have no effect on acute back pain

A recent study published in The journal found that lancetresearchers conducted a randomized controlled trial (RCT) in 157 primary care and emergency department (ED) facilities across Australia.

This study was the first placebo-controlled trial of an opioid for acute low back and neck pain.

study: A randomized trial found that opioids were as effective as placebo in relieving acute back pain. Image credit: fizkes/Shutterstock.com

Background

Several trials and systematic reviews have evaluated the use of opioids in patients with acute low back and neck pain, but RCTs with similar evaluations are lacking.

Nonetheless, it is important to assess the efficacy of opioid therapy, as it may provide long-term indefinite pain relief in these patients.

About research

Caitlin Jones and colleagues conducted a placebo-controlled trial of opioids for acute low back and neck pain. The researchers recruited patients who had mild to moderate back pain or neck pain but had been pain-free for at least the past month, prior to the onset of current spinal pain.

The primary endpoint of this study was the measurement of pain intensity 6 weeks after randomization. The research team randomized all participants to receive opioid therapy, a slow-release regimen of oxycodone and naloxone, adjusted every 7 to 14 days.

They started with a dose of 5 mg of drug twice daily. They adjusted the dose to 10 mg twice daily until pain intensity decreased to 0 or 1 on a 10-point scale after 5 weeks of oxycodone exposure if the participant reduced the dose for more than 1 week. bottom. They also provided naloxone to prevent constipation and improve blindness.

All participants received care that mimicked current primary care clinical practice.

Test results

The OPAL trial yielded two notable findings.

First, two to four weeks of opioid therapy did not improve physical function, quality of life, time to recovery, or absenteeism (overall outcome) in patients with acute back and neck pain.

Even after 6 weeks, opioid use did not provide relief or improvement in function compared to placebo, with a mean difference in pain between the two groups of 0.53 on a 10-point scale.

Another notable finding of the OPAL trial was that 25% of participants, 48 ​​to 174 and 40 to 172 in the opioid and placebo groups, began opioid misuse at week 52. be.

Although data were missing for 25% of participants in this trial, sensitivity and subgroup analyzes yielded consistent results. Also, the blindfold was almost successful.

Medication adherence was imperfect, but there was no difference between opioid and placebo recipients, and more importantly, doses of 20 to 40 mg morphine per day, or oxycodone, were adequate. .

Pain after an acute spinal cord injury is often chronic because it recurs, which can make opioid therapy ineffective.

Studies have also reported that back pain transforms over the course of a year into nociceptive pain, defined by changes in nociceptive processing. Therefore, patients with nociceptive pain syndrome, including those with chronic low back pain, also respond poorly to opioid therapy.

To measure substance abuse behavior in chronic pain patients whose physicians prescribe opioid therapy, researchers commonly use the Opioid Misuse Measurement (COMM).

In this study, 123 of 24 and 128 of 13 patients in the opioid and placebo groups scored 9 or higher on the COMM, indicating a high risk of opioid misuse and short-term opioid exposure. A notable finding for the associated low-risk group. past.

COMM is also investigating cognitive deficits and mood dependence that persist beyond the duration of opioid use—difficulties in thinking clearly and controlling anger. However, the authors were unable to determine the number of patients at high risk of opioid misuse at 52 weeks.

Conclusion

The OPAL trial is the first and only RCT to raise the need to reconsider current clinical guidelines recommending opioids for patients with acute low back and neck pain for whom other medications are ineffective or contraindicated.

Nonetheless, the trial showed that opioid therapy could provide primary care for up to 67% of patients with back or neck pain.