The purpose of this study is to evaluate etoricoxib efficacy in pain control, leg stiffness and functional recovery of patients suffering acute Achilles tendinopathy.

It is hypothesized that etoricoxib (120mg orally/day/7 days) efficacy is not inferior to diclofenac (150mg orally /day/7 days) for pain control in subjects suffering acute Achilles tendinopathy.

Inclusion Criteria:

• Patients are eligible if they are male between 18 and 50 years of age and they suffer acute Achilles tendinopathy (<2 weeks). Diagnosis of Achilles tendinopathy is made by means of activity-related achillodynia, morning stiffness or pain, painful one-legged jumping test, tenderness and decreased sports performance (26). Subjects' age, race, affected tendon (right, left), activity, height and weight will be recorded.

Exclusion Criteria:

• Patients are excluded from the study if they have:
• Prior lower limb surgery or major trauma.
• Bilateral Achilles tendinopathy.
• History of lower limb radiculo-neuropathy or miopathy.
• Hypersensitivity to any NSAIDs.
• Used analgesic agents (NSAIDs, salicilates, narcotic) within 1 week
• Concurrent medical/arthritic disease (e.g. gout, lupus, rheumatoid arthritis).
• Other concurrent medical conditions including diabetes, hypertension, angina or congestive heart failure, ischaemic cardiopathy, malabsorption, morbid - Personal history of renal dysfunction, hepatic dysfunction or anemia
• Used corticosteroids, clopidogrel bisulphate, rifampin, quinolon antibiotics, antiepileptics, muscle relaxants, warfarin, ticlopidine, glucosamine, condroitin sulphate for < 6 months prior to the study start. Patients taking low dose aspirin (100 mg) for cardioprotective benefit will be also excluded. Any other medication consumption will be considered by the investigator and the Ethical Committee.
• Any other condition which, in the opinion of the investigator, could confound the study results or pose a risk to the patient (for example, co-morbid conditions for which NSAIDs are contraindicated).
• History of psychotic illness, dementia or depression
• History of drug or alcohol abuse or dependence.
• Participated in any previous NSAIDs study and received active treatment, or in an investigational trial within 30 days prior to the first visit.
• Inability to communicate or to cooperate with the investigator.