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

Abstract

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.

Inferential reproduction analysis demonstrated that “paracetamol for acute low back pain” trial conclusions were reproducible

“…Although method reproducibility and inferential reproducibility have now been addressed for the PACE trial, results reproducibility (also called replication) has not [8,10,11]. However, a recent study by Friedman et al compared the combination of the NSAID ibuprofen and paracetamol with the combination of ibuprofen and placebo for patients with acute LBP reporting to two American emergency departments [36]. Although the research question, setting, patient population, and follow-up time were different from the PACE trial, the conclusions regarding the efficacy of paracetamol were the same as those made in the original PACE study.…”

The Lancet Series call to action to reduce low value care for low back pain: an update

“…This was most convincingly demonstrated in a series of trials by Friedman et al examining patients presenting to the emergency department with low back pain. 31 , 32 , 34 , 33 The SPACE trial also showed that an opioid strategy was not more effective than a nonopioid strategy in patients with chronic low back pain (or moderate to severe pain from knee or hip osteoarthritis), while it was also more likely to cause adverse events. 58 …”

Paracetamol for low back pain: the state of the research field

“…The studies by Nadler, and Williams were included in the Cochrane review [23][24][25]. The study by Friedman was published afterward [27]. Table 1 illustrates the overall limited evidence available comparing paracetamol versus placebo.…”

“…The two remaining trials show that there is no difference in effect of paracetamol versus placebo. This holds true for paracetamol taken regularly, as needed and as addition to Ibuprofen [24,27]. For chronic low back pain, there was only one trial, but the publication of this study has been retracted [26], thus for chronic low back there is no good evidence for or against the efficacy of paracetamol available.…”