Citation: Friedman BW, Cisewski D, Irizarry E, et al. A Randomized, Double-Blind, Placebo-Controlled Trial of Naproxen With or Without Orphenadrine or Methocarbamol for Acute Low Back Pain. Ann Emerg Med. 2018;71(3):348-356.e5. doi:10.1016/j.annemergmed.2017.09.031

Link: https://pubmed.ncbi.nlm.nih.gov/29089169/

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Article Summary:

This article is a randomized, double-blind, placebo-controlled trial assessing the use of Naproxen and placebo versus Naproxen and a muscle relaxer (Orphenadrine or Methocarbamol) in patients with acute lower back pain. I chose this article because of a patient I saw, who came into the office with back pain and neck pain two days after a motor vehicle accident (H&P #1). While she did not get treated in the emergency department, which is where this trial took place, she did have acute low back pain in the outpatient setting and was treated with Naproxen. I therefore decided to choose this article because I wanted to learn about the effectiveness of adding a muscle relaxer, as this was a treatment the physician and I discussed.

Patients, age 18-69, who were discharged with musculoskeletal (nontraumatic, nonradicular) low back pain from Montefiore Medical Center in the Bronx were enrolled in the study, with a total of 234 patients analyzed. To be included in this study, patients needed a baseline score of greater than five on the Roland Morris Disability Questionnaire (RMDQ), which is 24 questions to assess a patient’s functional status caused by back pain. The pain had to be occurring for less than two weeks and patients could not be pregnant or breastfeeding or have chronic pain syndrome or allergies to the medications used in this trial. The patients had follow up telephone calls at 7 days and 3 months. Patients received either Naproxen and placebo, Naproxen and Orphenadrine, or Naproxen and Methocarbamol for seven days. The primary outcome of this trial was improvement in the disability questionnaire between emergency department discharge and one week follow up, with secondary outcomes including frequency of back pain, frequency of follow-up visits, number of days until returning to usual activities.  

Follow up one week after emergency department visit showed that patients with Naproxen and placebo improved by an average of 10.9 RMDQ points, whereas orphenadrine patients improved by 9.4 points and methocarbamol patients improved by 8.1 points. Most patients used Naproxen and their second medication once a day or more than once a day. Patients were not required to use each medication on a regular schedule. There were no serious adverse effects within the first week while using these medications and the only side effect reported by more than two participants was nausea. When assessing these participants three months after the emergency department visit, most patients had a complete recovery. However, about 25% of those in the trial did reports RMDQ scores greater than eight, which indicates substantial functional impairment. Ultimately, this trial found that adding skeletal muscle relaxants to naproxen therapy for acute, nontraumatic, nonnradicular low back pain did not improve functional status or pain outcomes.

There were limitations to this study that should be addressed. First, this was a small population of about 240 participants, but since it was inclusive of the New York City region, I thought it was an appropriate article to discuss. As stated before, this was an article assessing acute low back pain in the emergency department, not an outpatient clinic. However, because I wanted to assess the treatments prescribed, I found there to be similarities in how the patient in my case would have been treated if also prescribed a muscle relaxant. Acute low back pain is a common complaint and understanding the best combination of medications with maximum benefit and minimal side effects or addictive properties is essential in both the emergency department and in primary care. Further studies into dosing and a regular scheduled regimen would be needed to assess if there is any extra effectiveness of the addition of a muscle relaxant to an NSAID like Naproxen.