A Blinded, Randomized Controlled Trial of Opioid Analgesics for the Management of Acute Fracture Pain in Adults Discharged From the Emergency Department

Introduction :Pain is a major symptom of many patients presenting to the emergency department (ED), with up to 42% of ED visits being related to painful conditions. ED providers are challenged with how best to treat acute pain, specifically when non-opioid analgesics are ineffective or contraindicated. There is considerable debate regarding most appropriate choice of analgesic when treating acute pain. Providers seek to prescribe the most effective analgesic with the least side effects, including the least risk of opioid dependence. Factors contributing to debate around the most appropriate opioid analgesic have also been influenced by pharmaceutical industry marketing and health care systems' efforts to improve clinicians' treatment of pain.

Ontario's most commonly prescribed opioid is codeine. Yet, its utilization as an analgesic is debated in the analgesic literature. Codeine is a prodrug that is metabolized to morphine in the liver. In most people, 5% to 10% of codeine is converted to morphine. Thus, some experts suggest that a 30 mg dose of codeine is considered equivalent to a 3 mg dose of morphine. However, other experts in this area suggest equi-analgesic doses of opioids are equally efficacious in relieving pain. In fact, codeine has been compared to hydrocodone using morphine-equivalent doses and were found equally efficacious at relieving pain the ED in a randomized controlled trial. Two additional randomized controlled trials have compared short acting hydrocodone and short acting oxycodone found them to be equally effective to relieve pain.

Another recent study by Chang et al., reported no statistically significant or clinically important differences in pain reduction at 2 hours after single-dose treatment with ibuprofen and acetaminophen or with 3 different opioid and acetaminophen combination analgesics for patients presenting to the ED with acute extremity pain. The largest difference in decline in mean pain score between any two treatments was 0.9 at the 2-hour time point, a difference that was not statistically significant and was less than 1.3, which was the author's a priori criterion to define a minimal clinically important difference in pain. This study had several limitations including the limited follow-up time of 2 hours, lack of adverse event reporting, and the exclusion of patients over the age of 65 years. This study is one of the only published randomized trials evaluating analgesic efficacy of opioid and non-opioid analgesics for an acutely painful condition.

There is a surprising paucity of studies evaluating analgesic efficacy, particularly after ED discharge, and there are no guidelines informing best practice for the management of acute pain following ED disposition for acute pain. To date, there have not been studies directly comparing the 3 most commonly prescribed opioids in Canadian EDs: codeine, hydromorphone and oxycodone. In light of mounting concern about the misuse of oral opioids, studies are needed to inform policy makers and to assist physicians in making evidence-based decisions about optimal short-term outpatient pain management.

There remains a paucity of data informing ED providers of opioid efficacy and patient important, functional outcomes in adults. Therefore, the objective of this study is to identify a preferred prescribed oral opioid analgesic for outpatient pain management among adults presenting to the ED with an acutely painful condition.