The Efficacy and Safety of a Combination of Thiocolchicoside and Etoricoxib in Low Back Pain (ESCoTEL): A Randomized Active-Controlled Trial

Background Low back pain (LBP) is a global health concern. Management of LBP aims at pain relief facilitating improvement of functional ability. Non-steroidal anti-inflammatory drugs (NSAIDs) are the first line of therapy. However, the selection of NSAIDs is challenging given the range of underlying etiologies and severity. The current study aimed to compare the efficacy and safety of two available fixed-dose combinations (FDCs), namely, a dual FDC (DFC) of etoricoxib (60 mg) and thiocolchicoside (4 mg) versus a triple FDC (TFC) of chlorzoxazone (500 mg), diclofenac (50 mg), and paracetamol (325 mg). Methodology A total of 200 eligible adult subjects aged 18-70 years with a history of LBP and muscle spasm for ≤14 days and Wong-Baker Faces Pain score >4 were enrolled after obtaining written informed consent and randomized in a 1:1 allocation ratio to be treated with either DFC or TFC for 28 days. Efficacy was assessed based on the change in score from baseline (before treatment) to day 28 on the Wong-Baker Faces Pain Scale and the Oswestry Disability Index (ODI) questionnaire, as well as the proportion of subjects who improved upon treatment. Safety was assessed based on adverse events and clinical laboratory test results. Results A significant decrease in pain intensity (p < 0.001) and significant improvement in functional ability (p < 0.001) was observed after treatment with either DFC or TFC. The decrease in Wong-Baker Faces Pain score and ODI, from baseline, was comparable between the treatment groups. However, more subjects with very severe pain at baseline showed ≥30% improvement upon treatment with DFC than with TFC (~25% versus ~12%; p = 0.172). Also, significantly more crippled subjects with very severe functional disability showed improvement in the DFC group compared to the TFC group (~26% versus ~4%; p = 0.008). No adverse events or clinically relevant laboratory test results were evident. Conclusions Both DFC and TFC were comparable in efficacy and safety for the management of recent-onset LBP. However, significantly more subjects with very severe pain or functional disability showed improvement after 28 days when treated with DFC compared to TFC.