Clinical Question

What is the optimal medication regimen for treating adults with acute low back pain (LBP)?

Bottom Line

Naproxen alone is as effective as naproxen plus oxycodone/acetaminophen or naproxen plus cyclobenzaprine (Flexeril) in reducing pain and improving function in adults with acute musculoskeletal LBP without radicular symptoms. Adverse events were significantly more common in patients additionally treated with either muscle relaxants or opioids. Be sure to note the exclusion criteria in the synopsis. (Level of Evidence = 1b)

Synopsis

Clinicians commonly treat acute LBP with a combination of nonsteroidal anti-inflammatory drugs, muscle relaxants, and opioids. These investigators identified adults (N = 323), 21 to 64 years of age, presenting to the emergency department for LBP clinically diagnosed as acute musculoskeletal LBP, defined as pain between the lower border of the scapulae and the upper gluteal folds. Exclusion criteria included radicular pain below the gluteal folds, direct trauma to the back within the previous month, pain duration longer than two weeks, and recent history of more than one LBP episode per month. Eligible patients randomly received (concealed allocation assignment) naproxen, 500 mg twice daily for 10 days, plus either placebo, 5 mg of cyclobenzaprine, or 5 mg of oxycodone/325 mg of acetaminophen, all taken as one or two tablets every eight hours. Individuals masked to treatment group assignment assessed pain and functional outcomes seven days and three months after emergency department discharge using a validated scoring tool. Complete follow-up occurred for 96% of participants at seven days and 87% at three months.

Using intention-to-treat analysis, there were no significant differences in pain and function scores between the three treatment groups at seven days and at three months of follow-up. Use of additional health care resources was uncommon but not significantly different between the three groups. However, adverse effects, including drowsiness, dizziness, dyspepsia, and nausea or vomiting, were significantly increased for oxycodone/acetaminophen (number needed to treat to harm [NNTH] = 5.3; 95% confidence interval [CI], 3 to 14) and cyclobenzaprine (NNTH = 7.8; CI = 4 to 129) compared with naproxen plus placebo.

Study design: Randomized controlled trial (double-blinded)

Funding source: Unknown/not stated

Allocation: Concealed

Setting: Emergency department

Reference: FriedmanBWDymAADavittMet alNaproxen with cyclobenzaprine, oxycodone/acetaminophen, or placebo for treating acute low back pain: a randomized clinical trial. JAMA2015; 314( 15): 1572– 1580.