Poster Presentation Sydney Spinal Symposium 2023

Randomized placebo-controlled trial of opioid analgesia for acute low back pain and neck pain – the OPAL trial (#29)

Caitlin Jones 1 , Richard Day 2 , Bart Koes 3 , Jane Latimer 1 , Christopher Maher 1 , Andrew McLachlan 4 , Laurent Billot 5 , Sana Shan 5 , Christine Lin 1
  1. Sydney Musculoskeletal Health, Institute for Musculoskeletal Health, The University of Sydney, Sydney Local Health District, Institute for Musculoskeletal Health, The University of Sydney, Camperdown, NSW, Australia
  2. Department of Clinical Pharmacology & Toxicology, St Vincent's Hospital Sydney and St Vincent’s Clinical Campus, Faculty of Medicine, University of New South Wales, Gadigal Country, Sydney, NSW, Australia
  3. Department of General Practice, Erasmus MC, Rotterdam, The Netherlands and the Center for Muscle and Joint Health, University of Southern Denmark, Odense, Denmark, Rotterdam, The Netherlands
  4. Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Gadigal Country, Sydney, NSW, Australia
  5. The George Institute for Global Health, Faculty of Medicine and Health, University of New South Wales, Gadigal Country, Sydney, NSW, Australia

Background: Opioid analgesics are commonly used for acute low back pain and neck pain, but supporting efficacy data are lacking.

Methods: In a triple-blinded, placebo-controlled trial, participants presenting to one of 157 primary care or emergency departments sites in Australia with ≤12 weeks of low back and/or neck pain were randomized (1:1) 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. Secondary outcomes included physical function, quality of life, adverse events, and risk of misuse. Outcomes were collected up to 52 weeks. All analyses were performed on an intention-to-treat basis. The trial was pre-registered (ACTRN12615000775516).

Results: 347 participants were recruited with a target sample size of 346 (the last two were recruited simultaneously)(n = 174 in opioid group, 173 in placebo group, between 29/02/16 and 10/03/21). There was no significant difference in pain between groups at 6-weeks (Mean Difference (MD) Opioid-Placebo 0·53 on a 10-point scale, 95% Confidence Interval (CI) -0·00 to 1·07, p = 0·051); but this increased over time and by 52-weeks there was a small difference favoring placebo (MD 0·57, 95% CI 0·02 to 1·11, p = 0·041). Taking opioids did not increase the risk of adverse events overall (61 (35%) participants in the opioid group reported at least one adverse event and 51 (30%) in the placebo group, p = 0·30), but more people in the opioid group reported opioid-related adverse events (e.g. constipation).

Conclusion: Opioids should not be recommended for acute non-specific low back pain or neck pain.

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

 

Trial registration: ACTRN12615000775516