Opioids: little benefit for muscle pain

Opioids are commonly prescribed and used for the management and treatment of muscle pain in humans. Research is showing, however, that they work no better for muscle pain than other safer treatments. While opioids can be effective, for instance, for “short-term relief of other types of severe pain, such as right after surgery and with broken bones” (Dr. Hance Clarke, medical director of the pain research unit at University Health Network in Toronto), they can also be dangerous. Opioids are highly addictive, plus people can develop tolerance to their effects (needing more and more of the drug to achieve the same result). The overprescribing and overuse of opioids has been a terrible problem in the United States and elsewhere.

Featured article:

*Jones, C. M. P., Day, R. O., Koes, B. W., Latimer, J., Maher, C. G., McLachlan, A. J., Billot, L., Shan, S., Lin, C. C., & OPAL, I. C. (2023). Opioid analgesia for acute low back pain and neck pain (the OPAL trial): a randomised placebo-controlled trial. Lancet. [Cited by]

“Background: Opioid analgesics are commonly used for acute low back pain and neck pain, but supporting efficacy data are scarce. We aimed to investigate the efficacy and safety of a judicious short course of an opioid analgesic for acute low back pain and neck pain.

Methods: OPAL was a triple-blinded, placebo-controlled randomized trial that recruited adults (aged ≥18 years) presenting to one of 157 primary care or emergency department sites in Sydney, NSW, Australia, with 12 weeks or less of low back or neck pain (or both) of at least moderate pain severity. Participants were randomly assigned (1:1) using statistician-generated randomly permuted blocks to guideline-recommended care plus an opioid (oxycodone–naloxone, up to 20 mg oxycodone per day orally) or guideline-recommended care and an identical placebo, for up to 6 weeks. The primary outcome was pain severity at 6 weeks measured with the pain severity subscale of the Brief Pain Inventory (10-point scale), analyzed in all eligible participants who provided at least one post-randomization pain score, by use of a repeated measures linear mixed model. Safety was analyzed in all randomly assigned eligible participants.

Findings: Between Feb 29, 2016, and March 10, 2022, 347 participants were recruited (174 to the opioid group and 173 to the placebo group). 170 (49%) of 346 participants were female and 176 (51%) were male. 33 (19%) of 174 participants in the opioid group and 25 (15%) of 172 in the placebo group had discontinued from the trial by week 6, due to loss to follow-up and participant withdrawals. 151 participants in the opioid group and 159 in the placebo group were included in the primary analysis. Mean pain score at 6 weeks was 2·78 (SE 0·20) in the opioid group versus 2·25 (0·19) in the placebo group (adjusted mean difference 0·53, 95% CI –0·00 to 1·07, p=0·051). 61 (35%) of 174 participants in the opioid group reported at least one adverse event versus 51 (30%) of 172 in the placebo group (p=0·30), but more people in the opioid group reported opioid-related adverse events (eg, 13 [7·5%] of 174 participants in the opioid group reported constipation vs six [3·5%] of 173 in the placebo group).

Interpretation: Opioids should not be recommended for acute non-specific low back pain or neck pain given that we found no significant difference in pain severity compared with placebo. This finding calls for a change in the frequent use of opioids for these conditions.

This article has been added to the Opioids, addiction, and overdose biblliography (Science Bibliographies Online).

Questions? Please let me know (engelk@grinnell.edu).