Ibuprofen Plus Acetaminophen Versus Ibuprofen Alone for Acute Low Back Pain: An Emergency Department-based Randomized Study

Objectives: Patients with low back pain (LBP) are often treated with nonsteroidal anti-inflammatory drugs (NSAIDs). NSAIDs are modestly effective for LBP, but many patients with LBP continue to suffer despite treatment with these medications. We compared pain and functional outcomes 1 week after emergency department (ED) discharge among patients randomized to a 1-week course of ibuprofen plus acetaminophen versus ibuprofen plus placebo.

Methods: This was a randomized, double-blind study conducted in two urban EDs. Patients presenting with acute, nontraumatic, nonradicular LBP of no more than 2 weeks' duration were eligible for enrollment immediately prior to discharge from an ED if they had a score > 5 on the Roland Morris Disability Questionnaire (RMDQ), a 24-item validated instrument, indicating more than minimal functional impairment. All patients were given a standardized 10-minute LBP educational session prior to discharge. The primary outcome was improvement on the RMDQ between ED discharge and 1 week later. One secondary outcome was pain intensity, as measured on a 4-point descriptive scale (severe, moderate, mild, none) at 1 week.

Results: Enrollment began in October 2018. A total of 120 patients met selection criteria and were randomized. Baseline demographic characteristics were comparable between the two groups. By 1 week after the ED visit, patients randomized to ibuprofen plus placebo reported a mean (±SD) improvement in the RMDQ of 11.9 (±9.7), while those randomized to ibuprofen plus acetaminophen reported a mean (±SD) improvement of 11.1 (±10.7). The 95% CI for the between-group difference of 0.8 was -3.0 to 4.7. At 1 week, moderate or severe pain was reported by 15 of 53 (28%) patients in the ibuprofen plus placebo group and 16 of 57 (28%) patients in the ibuprofen plus acetaminophen group (95% CI for between-group difference of 0% = -17% to 17%).

Conclusion: Among ED patients with acute, nontraumatic, nonradicular LBP, adding acetaminophen to ibuprofen does not improve outcomes within 1 week.