Primary Care Corner with Geoffrey Modest MD: Acute low back pain diazepam not help

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By Dr. Geoffrey Modest

An urban emergency room study found lack of utility of diazepam in patients with acute low back pain (see doi.org/10.1016/j.annemergmed.2016.10.002).

Details:

  • 114 patients with acute, nontraumatic, nonradicular low back pain (LBP) of <2 weeks and Roland-Morris Disability Questionnaire (RMDQ) >5 points (a 24-item patient self-administered questionnaire score which measures functional disability, with questions like “I stay at home most of the time because of the pain in my back”, where a 5 point change is considered clinically significant).
  • Mean age 36, 55% male, 73% worked >30hrs/week; median RMDQ score in the ER was 18 [which means substantial functional disability], median duration of LBP before coming to ER 2.5 days, 45% no prior history of LBP/ 48% “few times before”, 5% depressed
  • Randomized to naproxen 500mg bid prn, with either diazepam 5mg or placebo, to take 1-2 tabs every 12 hours prn. All patients got a 10-minute LBP educational session

Results:

  • 112 patients (98%) provided 1-week follow-up
  • At 1 week:
    • Frequency of med use:
      • Naproxen: 70% more than 1x/d, 17% 1x/d
      • Diazepam: 38% more than 1x/d, 32% 1x/d
      • Placebo: 38% more than 1x/d, 29% 1x/d
    • 18 of 57 patients on diazepam (32%) reported moderate or severe LBP
    • 12 of 55 on placebo (22%) had moderate or severe LBP
  • At 3 months:
    • 6 of 50 patients on diazepam (12%) reported moderate or severe LBP
    • 5 of 53 on placebo (9%) had moderate or severe LBP
  • Adverse events: 12 of 57 on diazepam (21%) vs 8 of 55 on placebo (15%)

Commentary:

  • LBP leads to 2.4% of all ER visits (2.7 million annually)
  • Of those presenting with acute LBP, most recover, though 20% have moderate to severe LBP-related functional impairment at 3 months
  • Benzos are sometimes prescribed for sleep and well as for “muscle relaxation”, though the data to support benefit are meager at best. And diazepam is prescribed in about 300,000 ER visits for LBP annually. Hence this study – which showed no benefit but more adverse effects with diazepam
  • The authors comment that most medications do not improve low back pain (see relevant blogs below), also including steroids or acetaminophen; that complimentary therapies (acupuncture, yoga, massage) have little data to support (see blog below on the AHRQ review), and that spinal manipulation is unlikely to benefit ER patients with acute low back pain.
  • This is the same ER group that did a similar study a couple of years ago looking at the efficacy of adding cyclobenzaprine or oxycodone/acetaminophen to naproxen for the same issue (see Friedman BW JAMA 2015; 314(15): 1572), briefly:
    • 323 patients with nontraumatic, nonradicular LBP for < 2 weeks’ duration, given naproxen 500mg bid plus either placebo, cyclobenzaprine 5mg or oxycodone 5mg/acetaminophen 325, to take 1-2 tablets of these q8h as needed, along with a 10 minute LBP educational session
    • They assessed pain by the Roland-Morris Disability Questionnaire (RMDQ), as above
    • Results: at 1-week follow-up, no significant difference between groups, as follows:
      • Naproxen: 72% of patients took naprox >1x/d, 13% took it 1x/d
      • Naproxen, along with:
        • Placebo: RMDQ improved 9.8 points (33% took placebo > 1/d, 31% 1/d)
        • Cyclopbenzaprine: RMDQ improved 10.1 points (31% took it > 1/d, 38% 1/d), more adverse effects than placebo by 13%, NNH (number needed to harm) =7.8
        • Oxycodone/acetaminophen: RMDQ improved 11.1 points (32% took it > 1/d, 21% 1/d), more adverse effects than placebo by 19%, NNH =5.3
      • Overall about 2/3 of patients reported clinically significant improvement 1 week later, though 40% reported moderate or severe pain
      • Also no difference at 3 months, though about ¼ of the patients still reported moderate or severe LBP
    • So, similar to the diazepam study: no evident benefit from either cyclobenzaprine nor oxycodone (though notable perhaps that relatively few patients took the meds much)
    • It should be noted in the oxycodone study that, of multiple exploratory analyses, one did show modest pain relief in the group who took oxycodone more than 1x/d, though the NNT was 6 and the NNH was 5.  So they could not exclude the possibility of modest benefit in those taking more oxycodone
    • See https://stg-blogs.bmj.com/bmjebmspotlight/2015/11/06/primary-care-corner-with-geoffrey-modest-md-opiates-for-acute-low-back-pain/ for a more complete analysis of this study
    • And other studies have not found benefit of the combo of NSAIDs with cyclobenzaprine (either one seems to be equally effective, the combo doesn’t add much)

 

So, these studies do add to the approach to acute low back pain: adding “muscle relaxants” to NSAIDs does not add any clear benefit but does add harms (though another study did find benefit of cyclobenzaprine by itself). And acute treatment by oxycodone, at least in the doses they prescribed, also showed no clear benefit. I would add to this the results from a few other blogs:

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