In a 12-week trial conducted in Australia, opioids were no better than placebo for relief of acute low back pain and neck pain, researchers report. “Opioids should not be recommended for acute non-specific low back pain or neck pain,” the investigators conclude. “This finding calls for a change in the frequent use of opioids for these conditions.”
In the OPAL trial, adults at 157 primary care or emergency department sites in Sydney were recruited when they had low back or neck pain (or both) for 12 weeks or less of at least moderate severity. Participants were randomized to triple-blinded 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.
Based on safety and a primary outcome of pain severity at 6 weeks measured with the pain severity subscale of the Brief Pain Inventory (10-point scale), the study showed the following: “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).”