Topical Diclofenac Versus Oral Ibuprofen Versus Diclofenac + Ibuprofen for Emergency Department Patients With Acute Low Back Pain: A Randomized Study

Abstract

IntroductionTopical non-steroidal anti-inflammatory drugs (NSAIDs) are useful for a variety of musculoskeletal injuries. It is not known whether topical NSAIDs should be used for patients presenting with acute non-radicular musculoskeletal low back pain (LBP). MethodsWe conducted a randomized, placebo-controlled double-blind study in which ED patients 18-69 years with acute, non-traumatic, non-radicular, musculoskeletal LBP were randomized at the time of discharge to treatment with oral ibuprofen 400mg orally + placebo topical gel, 1% diclofenac topical gel + oral placebo, or ibuprofen 400mg + 1% diclofenac topical gel. We measured outcomes using the Roland Morris Disability Questionnaire (RMDQ), a 24-item yes/no instrument about the impact of back pain on a respondent’s daily activities. The primary outcome was change in RMDQ between ED discharge and two days later. Medication related adverse events were elicited by asking whether the study medications caused any new symptoms. Results3281 patients were screened for participation and 198 were randomized. Overall, 36% of the population were women, the mean age was 40 years (SD 13), and the median RMDQ score at baseline was 18 (25th, 75th percentile: 13, 22) indicating substantial low back related functional impairment. 183 (92%) participants provided primary outcome data. By two days after the ED visit, the ibuprofen + placebo group had improved by 10.1(95%CI 7.5 to 12.7), the diclofenac gel + placebo group by 6.4(95%CI 4.0 to 8.8), and the ibuprofen + diclofenac gel by 8.7(95%CI 6.3 to 11.1). The 95%CI for between group differences were as follows-- ibuprofen versus diclofenac: 3.7 (0.2, 7.2); ibuprofen versus both medications 1.4 (-2.1, 4.9); diclofenac versus both medications -2.3 (-5.7, 1.0). Medication related adverse events were reported by 3/60 (5%) ibuprofen patients, 1/63 (2%) diclofenac patients, and 4/64 (6%) patients who got both. ConclusionsAmong patients with non-traumatic, non-radicular acute musculoskeletal low back pain discharged from an ED, topical diclofenac was probably less efficacious than oral ibuprofen. It demonstrated no additive benefit when co-administered with oral ibuprofen.