6 Nov, 15 | by EBM
By Dr. Geoffrey Modest
JAMA just published a randomized clinical trial on the use of opioids or cyclobenzaprine in addition to naproxen for patients going to the emergency room with acute low back pain (see JAMA. 2015;314(15):1572-1580).
- Setting: inner city ER in the Bronx, New York City, looked at patients with nontraumatic, nonradicular low back pain (LBP) of <2 weeks’ duration and had score >5 on Roland-Morris Disability Questionnaire (RMDQ), a 24-item instrument used to assess functional impairment in patients with LBP, with scores ranging from 0 to 24. A 5-point improvement is considered clinically significant
- 323 patients (mean age 39, 50% men, 45% never had LBP before and 12% had it >1x/year, 28% had on-the-job injury, 5% positive depression screen, and mean RMDQ was 20) were randomized to naproxen 500 bid, along with either placebo, cyclobenzaprine 5mg , or oxycodone/acetaminophen 5/325 mg (all to take 1-2 q8hrs as needed, 60 pills given). All received a standard 10-minute LBP educational session prior to discharge from the ER
- Patients were contacted 7 days and 3 months after the ER visit
- Results, assessed 1 week later:
- Mean RMDQ in placebo group = 9.8
- Mean RMDQ in cyclobenzaprine group = 10.1
- Mean RMDQ in oxycodone/acetaminophen group = 11.1
- None of these were a statistically significant difference in terms of functional pain
- At 7 days, 40% rated their pain as moderate-to-severe, >50% of those in each group continued to need pain meds after 7 days, and 70% would want the same treatment with subsequent LBP episodes (no significant difference between groups)
- Also no difference in use of health care resources (ER/primary care/specialty/PT visits), frequency of naproxen use or frequency of use of study med
- More than 75% took naproxen daily and 2/3 took it bid; only 1/3 used the study medicine >1x/day and 40% used it intermittently, though there was no significant difference in outcome if limit the analysis to those taking the study medicine >1x. Secondary analysis did find that of those who took their study meds >1x, more on opiates rated their pain as mild to none.
- More adverse events in those not on placebo (mostly drowsiness, dizziness, nausea/vomiting with oxycodone/acetaminophen; less impressive increase in drowsiness with cyclobenzaprine)
- 3 months later: 1 in 4 patients in each group still had moderate or severe LBP, and 2.3% were taking opioids. 80% of each group had resumed their usual activities and 80% were back to fulltime work. Again, no difference between the groups.
The JAMA authors cite other studies finding that 70% of patients still have functional impairment and continued analgesic use 1 week after an ER visit for acute LBP. Also, despite the prevalent usage, studies suggest that combining meds (e.g. cyclobenzaprine and opioids) is no more efficacious than prescribing monotherapy.
So, this article does raise a few issues:
- Most of these patients with pretty severe acute LBP did not take their full complement of pain medications (only 2/3 took the naproxen bid and most did not take their additional study med very much)
- In my (limited) experience, very few patients who go to the ER with acute low back pain do not leave without an array of scripts including opiates (and I have seen several patients who were given opiate meds even though they explicitly asked not to get them, with “well, take the prescription anyway, just in case you need it….”). This and other studies suggest that polypharmacy does not add anything
- It is impressive but not surprising that 1 week later, there was pretty dramatic improvement in the disability scores. But it seemed that adding the cyclobenzaprine or oxycodone did not seem to add anything to the naproxen.
- One difficult issue for some patients might be to convince them that simple over-the-counter remedies (e.g. naproxen, or even acetaminophen from other studies) is sufficient to treat their pretty disabling pain. But, perhaps a persuasive “this is really the best medication for you, works as well as any other medication, and has many fewer side-effects than the others” may work (we have had pretty good success with a similar line of argument in decreasing the use of antibiotics for viral illnesses, esp. when given in a positive, reasonably exuberant and reassuring fashion).
For my litany of articles on chronic pain management, see http://blogs.bmj.com/ebm/category/pain/, and especially http://blogs.bmj.com/ebm/2015/06/17/primary-care-corner-with-geoffrey-modest-md-mass-med-society-opioid-prescription-guidelines/ and http://blogs.bmj.com/ebm/2015/03/16/primary-care-corner-with-geoffrey-modest-md-feel-good-gene/