A randomized controlled trial of oxycodone/acetaminophen versus acetaminophen alone for emergency department patients with musculoskeletal pain refractory to ibuprofen.

BACKGROUND

Use of oral opioids does not result in more pain relief than nonopioid alternatives when administered to patients as first-line treatment for acute musculoskeletal pain. This study compared the efficacy of oxycodone/acetaminophen to that of acetaminophen alone as second-line treatment for patients with acute musculoskeletal pain who were administered prescription-strength ibuprofen and reported insufficient relief 1 h later.

METHODS

A randomized, double-blind study was conducted in two urban emergency departments. Opioid-naïve patients ≥ 18 years with an acute musculoskeletal injury were administered ibuprofen 600 mg as part of the study protocol. Those who reported insufficient relief 1 h later were randomized (1:1 ratio) to oxycodone 10 mg/acetaminophen 650 mg or acetaminophen 650 mg. The primary outcome was improvement in 0 to 10 pain scale between randomization and 2 h later. We also assessed medication-associated adverse events. A sample size calculation, built around a minimum clinically important difference of 1.3 units, determined the need for 154 patients.

RESULTS

We screened 924 patients and enrolled 393. All 393 received ibuprofen. A total of 159 (40%) patients reported inadequate relief after 1 h had elapsed. A total of 154 of these were randomized, 77 to oxycodone/acetaminophen and 77 to acetaminophen. Baseline characteristics were comparable. Among patients randomized to oxycodone/acetaminophen, mean (±SD) improvement in 0 to 10 pain scale was 4.0 (±2.6) versus 2.9 (±2.4) in the acetaminophen arm. The 95% confidence interval (CI) for the mean difference of 1.1 was 0.3 to 1.9. Among patients who received oxycodone/acetaminophen, 26 of 76 (34%) reported any medication-related adverse event versus seven of 74 (9%) participants who received acetaminophen. The 95% CI for the between-group difference of 25% was 12% to 37%).

CONCLUSION

Among patients with acute musculoskeletal pain refractory to oral ibuprofen, oxycodone/acetaminophen resulted in slightly greater pain relief than acetaminophen, but this was associated with more medication-related adverse events.