A Randomized Study of Three Medication Regimens for Acute Low Back Pain

Low back pain causes 2.4% of visits to US emergency departments (ED) resulting in 2.7 million
visits annually. In a general low back pain (LBP) population, prognosis is poor. About 50% of
patients who visited general practitioners with new onset musculoskeletal LBP report
persistent pain and functional disability three months after the index visit. Outcomes are
similarly poor for the population of patients forced to use an ED for management of their
LBP. In an observational study of patients with non-traumatic LBP recently completed at the
PI's institution, patients were contacted one week after ED discharge: 70% reported
persistent back-pain related functional impairment, 59% reported moderate or severe LBP, and
69% reported analgesic use within the previous 24 hours. Three months after the ED visit, 48%
reported functional impairment, 42% reported moderate or severe pain, and 46% reported
analgesic use within the previous 24 hours.

A variety of evidence-based medications are available to treat LBP. Non-steroidal
anti-inflammatory drugs (NSAID) are more efficacious than placebo with regard to pain relief,
global improvement, and requirement of analgesic medication. Skeletal muscle-relaxants too
are effective for short-term pain relief and global efficacy. Opioids are commonly used for
moderate or severe acute LBP,(9) though high-quality evidence supporting this practice is
lacking.

Treatment of LBP with multiple concurrent medications is common in the ED setting. Emergency
physicians often prescribe NSAIDs, skeletal muscle relaxants, and opioids in combination.
Several clinical trials have compared combination therapy with NSAIDS+ skeletal muscle
relaxants to monotherapy with just one of these agents. These trials have reported
heterogeneous results. The combination of opioids + NSAIDS has not been evaluated
experimentally in patients with acute LBP.

Given the poor pain and functional outcomes that persist beyond an ED visit for
musculoskeletal LBP, the investigators propose a clinical trial to evaluate whether combining
muscle relaxants or opioids with NSAIDs is more effective than NSAID monotherapy for the
treatment of non-traumatic, non-radicular low back pain. Specifically, the investigators will
evaluate three distinct hypotheses:

1. The combination of naproxen + cyclobenzaprine will provide greater relief of LBP than
naproxen alone seven days after an ED visit, as measured by the Roland Morris low back
pain functional disability scale

2. The combination of naproxen + oxycodone/ acetaminophen will provide greater relief of
LBP than naproxen alone seven days after an ED visit, as measured by the Roland Morris
low back pain functional disability scale

3. The combination of naproxen + oxycodone/ acetaminophen will provide greater relief of
LBP than naproxen + cyclobenzaprine seven days after an ED visit, as measured by the
Roland Morris low back pain functional disability scale