Efficacy and Safety of Etoricoxib/Betamethasone Combination in Acute Bursitis, Tendinitis and Synovitis

Inclusion Criteria: * Patients willing and able to participate in the study and provide written informed consent. * Male or female. * Age ≥ 18 years at study entry. * Women of childbearing potential who use an acceptable contraceptive method (barrier, oral hormonal, injectable, subdermal), or women who are naturally postmenopausal or surgically sterile. * Clinical diagnosis of an acute episode of tendinitis, bursitis, or synovitis of the shoulder, elbow, knee, or ankle, with onset within 7 days prior to the first dose of study medication. * A score ≥ 40 mm on a 100-mm Visual Analog Scale (VAS) for maximum pain intensity during active movement, as reported by the patient at the time of study inclusion. * In the opinion of the Principal Investigator or treating physician, the participant is an appropriate candidate for treatment with the investigational product. Exclusion Criteria: * Participation in another clinical study involving an investigational treatment, or participation in such a study within 4 weeks prior to study start. * Patients whose participation could be influenced (e.g., employment relationship with the study site or sponsor, vulnerable populations, etc.). * In the investigator's medical judgment, any disease that affects prognosis and prevents outpatient management, including but not limited to: terminal cancer, renal, cardiac, respiratory, or hepatic failure, mental illness, or scheduled surgical procedures or hospitalizations. * History or presence of any disease or condition that, in the investigator's opinion, could pose a risk to the patient or confound the efficacy and safety evaluation of the investigational product, such as significant degenerative disease or an infectious process in the joints of interest. * Fever: axillary temperature \> 37.5°C within 2 days prior to or at the time of study inclusion.- * Pregnant or breastfeeding patients. * Contraindication to the study medications. * History of allergic reaction to NSAIDs (non-steroidal anti-inflammatory drugs), paracetamol (acetaminophen), or known hypersensitivity to the study medications. * Significant history of gastrointestinal disorders (e.g., gastric ulcer, Crohn's disease, ulcerative colitis, gastrointestinal bleeding, etc.). * History of congestive heart failure (NYHA Class II-IV), established ischemic heart disease, peripheral arterial disease and/or cerebrovascular disease (including patients who have recently undergone coronary revascularization procedures or angioplasty). * Treatment with corticosteroids within 1 month prior to study start. * Treatment with NSAIDs within 48 hours prior to study start, except for cardioprotective-dose aspirin. * Tendinitis or bursitis secondary to a systemic inflammatory disease, or synovitis secondary to hemophilia. * History of harmful alcohol and/or drug use causing adverse health and social effects. * Clinical suspicion of joint infection or another joint disease other than tendinitis, bursitis, or synovitis. * History of chronic hepatic impairment (Child-Pugh A, B, and/or C). * History of acute renal failure or chronic kidney disease (glomerular filtration rate \< 30 mL/min/1.73 m²). * Significant history of known coagulation disorders (e.g., von Willebrand disease, hemophilia, vitamin K deficiency, etc.) or use of anticoagulants. * Oncology patients (except basal cell skin cancer or patients with cancer in remission) or patients with severe diseases that, in the investigator's opinion, have a poor prognosis or a life expectancy of less than 1 year, as well as mental illnesses.