In a placebo-controlled trial, topical diclofenac plus oral ibuprofen was not better than ibuprofen alone.

Most episodes of acute, nonradicular low back pain will improve, with or without treatment. For patients with low back pain, clinicians often prescribe a combination of oral and topical NSAIDs (with diclofenac as the typical topical agent). To find out whether this combination is effective, investigators in a single New York emergency department conducted a double­-blind randomised trial: 198 patients (mean age, 40 years) who presented with acute, nonradicular low back pain received a two-­day supply of oral ibuprofen (400 mg, every six hours as needed) plus topical placebo gel, topical diclofenac (1% gel) plus oral placebo, or ibuprofen plus diclofenac (combination treatment).

At two days, all treatment groups improved between six and 10 points on a 24-­point validated questionnaire: the ibuprofen group improved 3.7 points more than the diclofenac group (a statistically significant, but not clinically meaningful, difference). No significant differences were noted between ibuprofen and combination therapy. Functional scores continued to improve at seven days, with no important differences among the groups. Adverse effects were similar and mild in all groups.

Comment: In this trial, the combination of topical diclofenac plus oral ibuprofen was not superior to oral ibuprofen alone.

One limitation is that the study involved only active comparators, so improvement without any active treatment was not assessed. However, in a recent randomised trial, topical diclofenac was no better than placebo for managing acute back or neck pain (Pain Ther 2020; 9: 279-296). Thus, I see little downside to using topical diclofenac for acute low back pain, but any perceived effectiveness likely reflects a mix of placebo effect and spontaneous improvement.

Nolan J. Mischel, MD, Assistant Professor of Medicine, Texas Christian University, Burnett School of Medicine; Core Family Medicine Faculty, John Peter Smith Hospital, Fort Worth, USA.

Khankhel N, et al. Topical diclofenac versus oral ibuprofen versus diclofenac + ibuprofen for emergency department patients with acute low back pain: a randomized study. Ann Emerg Med 2024; 83: 542-551.

This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine.