Does the addition of cyclobenzaprine or oxycodone with acetaminophen to naproxen result in improved functional outcomes at one week when compared to placebo in patients with acute low back pain?

Friedman B, Dym A, Davitt, M, et al. Naproxen with cyclobenzaprine, oxycodone/acetaminophen, or placebo for treating acute low back pain: a randomized clinical trial. JAMA 2015:20;314(15):1572-80.

The primary objective of this study was to compare functional outcomes at one week and three months after emergency department (ED) presentation for acute low back pain among patients prescribed naproxen plus one of the following: (1) oxycodone/acetaminophen; (2) cyclobenzaprine; or (3) placebo.

We compared pain severity and time to resumption of activities in patients with cervical strains treated with a nonsteroidal anti-inflammatory drug (NSAID), a centrally acting muscle relaxant or both.

We performed a double-blinded, randomized controlled trial of adults with cervical strains from motor vehicle collisions or from falls who presented to a suburban academic emergency department (ED). Patients were randomly assigned to receive ibuprofen 800 mg, cyclobenzaprine 5 mg or both, 3 times daily as needed for up to 7 days. Outcome measures included a pain score on a 100-mm visual analog scale, pain relief scores, the time to resumption of normal activities, the use of rescue medications, and adverse outcomes. We used repeated-measures analysis of variance to compare pain relief over time. Our sample size of 20 patients in each group had a power of 80% to detect a difference of 15 mm in pain relief scores between the highest and lowest groups.

We randomly assigned 61 patients to receive ibuprofen (n = 20), cyclobenzaprine (n = 21) or both (n = 20). Mean (standard deviation) age was 34 (11) years; 58% were women and 72% were white. Although pain scores improved over time in all groups, there were no significant differences between the groups in any of the outcome measures. The rate of adverse events was also similar between groups.

Our study suggests that there is little benefit to routinely using or adding cyclobenzaprine to NSAIDs for ED patients with acute cervical strain.