Secondary outcomes. At 7 days, there was no significant difference between study groups in subjective pain assessment, frequency of LBP, or use of as-needed medications in the prior 24 hours. There was also no difference in the median number of days to return to work or need for follow-up health care visits. In patients who took more than one dose of the study medication, those who took oxycodone/acetaminophen were more likely to describe their worst pain in the last 24 hours as mild/none when compared to those taking placebo (number needed to treat [NNT]=6). About 72% of all subjects reported that they would choose the same treatment option again, with no difference between groups. At 3 months, no difference existed between groups in subjective pain assessment, frequency of LBP, use of as-needed medications, or opioid use during the previous 72 hours.
Adverse effects, including drowsiness, dizziness, stomach irritation, and nausea or vomiting, were more common in the oxycodone/acetaminophen and cyclobenzaprine treatment groups with a number needed to harm (NNH) of 5.3 and 7.8, respectively.
What’s New
A second pain reliever adds nothing—except adverse effects
This RCT found that adding cyclobenzaprine or oxycodone/acetaminophen to naproxen for the treatment of nontraumatic, nonradicular acute LBP did not significantly improve functional assessment based on RMDQ scores or pain measures at 7 days or 3 months after the initial ED visit. It did, however, increase adverse effects.
Caveats
Researchers studied a specific subset of patients
This study was performed in a single-site urban ED and included a very specific subset of LBP patients, which limits the generalizability of the results. However, patients often present to their primary care physician with similar LBP complaints, and the results of the study should reasonably apply to other settings.
The findings may not generalize to all NSAIDs, but there is no evidence to suggest that other NSAIDs would behave differently when combined with cyclobenzaprine or oxycodone/acetaminophen. In this intention-to-treat analysis, only about one-third of patients used the as-needed medication more than once daily; about another third of patients used the as-needed medication intermittently or never.
Challenges to Implementation
Patients may expect more than an NSAID for their back pain
Patients expect to receive prescriptions, and physicians are inclined to write them if they believe they will help their patients. The evidence, however, does not show a benefit to these prescription-only medications for low back pain.
ACKNOWLEDGEMENT
The PURLs Surveillance System was supported in part by Grant Number UL1RR024999 from the National Center For Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center For Research Resources or the National Institutes of Health.
