First placebo-controlled trial of opioid analgesia for acute spinal pain (OPAL)
Low back pain and neck pain are extremely prevalent and are responsible for an enormous burden of disease both in Australia and globally. Strong analgesics, such as opioid analgesics, are recommended by clinical practice guidelines as second line care for people with acute low back pain or neck pain who are slow to recover and require more pain relief. The latest Australian data suggest that opioid analgesics are now the most widely prescribed medicine for low back pain and neck pain in general practice.
Despite the widespread use, there are no randomised, placebo-controlled trials evaluating opioid analgesics for acute low back pain or neck pain. Concerns regarding opioid use are further heightened due to the risks of adverse events, some of which can be serious. Australian data point to an increase in opioid poisoning, while in the United States deaths from opioid analgesics have surpassed those of cocaine and heroin combined.
Given the lack of evidence on efficacy and concerns regarding safety, there is an urgent need to understand whether opioid analgesics are beneficial for patients with acute low back pain and/or neck pain. OPAL is a randomised, placebo-controlled, triple-blinded trial that will investigate the judicious use of an opioid analgesic in 346 participants with acute low back pain and/or neck pain who are slow to recover. Participants will be recruited from general practice and randomised to receive the opioid analgesic (modified-release oxycodone up to 20 mg per day) or placebo in addition to guideline care for up to 6 weeks. Participants will be followed for 3 months for effectiveness outcomes. The primary outcome will be pain severity. Medication-related adverse events will be assessed and a cost-effectiveness analysis will be conducted. We will additionally assess long-term use and risk of misuse of opioid analgesics for up to 12 months.
The results of this study will be critical in providing robust evidence to inform the quality use of opioid analgesia in acute low back pain and neck pain. The results will also influence international clinical practice guidelines and most importantly, improve care for patients suffering acute spinal pain.
