Opioid analgesia for acute low back pain and neck pain (the OPAL trial): a randomised placebo-controlled trial

Caitlin M P Jones; Richard O Day; Bart W Koes; Jane Latimer; Chris G Maher; Andrew J McLachlan; Laurent Billot; Sana Shan; Chung-Wei Christine Lin; OPAL Investigators Coordinators

doi:10.1016/S0140-6736(23)00404-X

Opioid analgesia for acute low back pain and neck pain (the OPAL trial): a randomised placebo-controlled trial

Lancet. 2023 Jul 22;402(10398):304-312. doi: 10.1016/S0140-6736(23)00404-X. Epub 2023 Jun 28.

Authors

Caitlin M P Jones¹, Richard O Day², Bart W Koes³, Jane Latimer¹, Chris G Maher¹, Andrew J McLachlan⁴, Laurent Billot⁵, Sana Shan⁵, Chung-Wei Christine Lin⁶; OPAL Investigators Coordinators

Collaborators

OPAL Investigators Coordinators:
Hanan McLachlan, Melissa Webb, Melanie Hamilton, Harbeer Ahedi, Angie Barber, Wendy Mak, Stephanie Mathieson, Veronika Petrova, Severine Bompoint, Sana Shan, Bridin Murnion, Nicholas Buckley, Apo Demirkol, Paul Wrigley, Christopher Needs, Louise Brooks, Samuel Cantori, Paul Preisz, James Aitken, Sujata Allan, Michael Burke, Greg Cameron, Francisco Javier Valencia Cepeda, Christopher Davis, Jayasree Dullur, Joseph Emmanuel, Catherine Errey, Sabine Fieuw-Makaroff, Adam Gaudry, L Genua, Ian Longhurst, Kenneth McCroary, Diana Merhi, Tanya Nguyen, Zahra Rassoly Obayd, Michelle Penm, Sharan Pobbathi, William S Poh, Paul Schnitzler, Sabiha Shahnaz, Ven Tan, Danny Tang, Brian Tan, Win Kyaw Thu, Thrasivolous Triantopolous, Ramana Venkatesan, Wicky Chun Fai Wong, Shu Ching Yang

Affiliations

¹ Sydney Musculoskeletal Health, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia; The Institute for Musculoskeletal Health, Sydney Local Health District, Sydney, NSW, Australia.
² Department of Clinical Pharmacology and Toxicology, St Vincent's Hospital Sydney and St Vincent's Clinical Campus, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
³ Department of General Practice, Erasmus MC, Rotterdam, Netherlands; Center for Muscle and Joint Health, University of Southern Denmark, Odense, Denmark.
⁴ Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia.
⁵ The George Institute for Global Health, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
⁶ Sydney Musculoskeletal Health, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia; The Institute for Musculoskeletal Health, Sydney Local Health District, Sydney, NSW, Australia. Electronic address: christine.lin@sydney.edu.au.

PMID: 37392748
DOI: 10.1016/S0140-6736(23)00404-X

Abstract

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 randomised 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), analysed in all eligible participants who provided at least one post-randomisation pain score, by use of a repeated measures linear mixed model. Safety was analysed in all randomly assigned eligible participants. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615000775516).

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.

Funding: National Health and Medical Research Council, University of Sydney Faculty of Medicine and Health, and SafeWork SA.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Acute Pain* / drug therapy
Adolescent
Adult
Analgesia*
Analgesics, Opioid / adverse effects
Australia
Female
Humans
Low Back Pain* / drug therapy
Male
Neck Pain / drug therapy
Oxycodone / adverse effects

Substances

Analgesics, Opioid
Oxycodone