Use of an opioid analgesic did not confer any benefits for adults with acute low back pain (LBP) or neck pain when compared to placebo, according to a new study published in The Lancet.
“This finding calls for a change in the frequent use of opioids for these conditions,” wrote Caitlin Jones, PhD, faculty of medicine and health at The University of Sydney, and colleagues.
Guideline-recommended care of acute LBP and neck pain suggest opioid analgesics only be used when other pharmacologic therapies are contradicted or have not worked, the authors stated. “The use of opioids for the management of acute low back pain and neck pain is not supported by direct and robust evidence,” noted researchers. Further, their use is associated with the risk of adverse events, including dependency, misuse, and overdose, they added.
Jones and colleagues conducted the OPAL (Opioid Analgesia for Acute Low Back Pain and Neck Pain) clinical trial to investigate the efficacy and safety of short-term use of opioid analgesics for the management of acute non-specific LBP and neck pain.
Between February 2016 and March 2022, investigators recruited 347 individuals aged ≥18 years who presented at one of 157 primary care or emergency department sites in Australia with ≤12 weeks of LBP or neck pain (or both) of at least moderate intensity. Participants were randomly assigned to receive guideline-recommended care plus either an opioid (n=174) or placebo (n=173) for up to 6 weeks. Participants in the opioid group received up to 20 mg of modified-release oxycodone-naloxone per day orally.
In the overall cohort, the mean age at baseline was 44 years and “no major differences were found in baseline characteristics, with age, BMI, pain location, and employment status being similar across groups,” added Jones and coauthors.
According to the study, the primary outcome was painseverity at 6 weeks measured with the pain severity subscale of the Brief Pain Inventory and investigators collected data up to 12 months.
Overall, 89% of participants (49% of the opioid group, 51% of the placebo group) were included in the primary analysis.
Results showed no significant difference in pain scores at 6 weeks between the 2 cohorts, with a score of 2.78 in the opioid group and 2.25 in the placebo group (adjusted mean difference 0.53, 95% CI -0.00 to 1.07; P=.051).
“Pain severity was not significantly different between groups at week 12. However, the between-group difference increased over time and by week 52 there was a small difference favoring placebo,” wrote investigators.
In addition, 35% of participants in the opioid group and 30% of those in the placebo group reported non-serious adverse events. The most common adverse events reported across both groups were nausea and vomiting, constipation, headache, dizziness, and somnolence. All of these events, except for headache, were more frequently reported in the opioid group than placebo group.
“We report a small but significant risk of harm at 1 year even after short-term use. This finding is counter to guidelines, which recommend that opioids can be used judiciously for acute back pain, given that we found that there are no benefits but there is risk of harm,” wrote Jones et al. “Our findings do, however, support the changes in guideline recommendations for low back pain management, which have seen a shift in focus from pharmacological to non-pharmacological treatments, such as physical and psychological therapies.”
References: Jones CMP, Koes BW, Latimer J, et al. Opioid analgesia for acute low back pain and neck pain (the OPAL trial): A randomised placebo-controlled trial. Lancet. Published online June 27, 2023. doi:10.1016/S0140-6736(23)00404-X.