Etoricoxib Versus Diclofenac Sodium Intramuscular Injections in Acute Orthopaedic Pain Management: A Randomized, Open-Label Pilot Trial

Abstract Background Acute orthopaedic pain is a common clinical challenge in emergency and inpatient settings, with the use of injectable non-steroidal anti-inflammatory drugs (NSAIDs) as the mainstay of pharmacological treatment. Although intramuscular diclofenac sodium has long dominated this therapeutic area, its non-selective inhibition of Cyclooxygenase-1 (COX-1) and Cyclooxygenase-2 (COX-2) enzymes raises safety concerns. An intramuscular formulation of etoricoxib, a highly selective COX-2 inhibitor, has recently become accessible, providing a mechanistically distinct alternative. Methods A prospective, open-label randomized controlled study was conducted in the outpatient orthopaedic department of a tertiary care hospital. 70 eligible patients were randomised into Group A (n = 35) receiving Intramuscular Etoricoxib (90mg) and Group B (n = 35) receiving Intramuscular Diclofenac Sodium (75mg), presenting with acute orthopaedic pain. Pain intensity scores were recorded using VAS and VNRS at baseline and follow-up post-administration. Adverse events were systematically monitored, including injection-site pain, gastrointestinal symptoms, renal function parameters, and hypersensitivity reactions. Statistical analysis was performed using Python (version 3.12). Results The mean age was 41.71 ± 15.63 years in Group A and 41.49 ± 13.87 years in Group B (p = 0.95). Both groups had a similar gender distribution with a slight female predominance. Both intramuscular etoricoxib and diclofenac sodium significantly reduced pain intensity from baseline at all post-injection time points (p < 0.0001). A statistically significant difference in pain intensity emerged at 12 hours. An exploratory secondary analysis of Drug x Time interaction in a repeated-measures ANOVA (F (4,272) = 7.795; p < 0.0001). Patients receiving etoricoxib reported a higher incidence of injection-site discomfort (68.57 vs. 42.86%; p = 0.03). No significant systemic adverse effects were reported in either group. Trial Registration Registered prospectively in Clinical Trial Registry India (CTRI) as CTRI/2025/07/091721 on 25th July,2025.