Evaluation of the Efficacy and Tolerability of Etoricoxib Monotherapy Versus Combination Oxycodone-etoricoxib in Moderate to Severe Pain From Chronic Low Back Pain

Inclusion Criteria: * Male or female outpatients (at least 18 years of age). * Patient with a confirmed diagnosis of moderate-to-severe CLBP present for more than 15 days per month and several hours per day for at least 6 months prior to screening. * Achieve at least 3 consecutive days with an average daily pain score \> 4 during baseline week (between visit 1 and visit 2) via patient diary recordings. * Patient is currently not receiving treatment for CLBP or was receiving treatment for CLBP, with a drug other than etoricoxib or oxycodone, and completed the required washout prior to Visit 2. * Patient has never received treatment with etoricoxib or oxycodone and other strong opioids. * No assumption of adjuvant drugs (antiepileptics, steroids, tricyclic antidepressants, SNRIs, muscle relaxants) in the last month (or two week). * Patient has a level of understanding sufficient to provide written informed consent and to communicate with the investigator and site personnel. * Patient is judged to be reliable, agrees to keep all appointments for clinic visits, and agrees to participate in recording responses to questionnaires and other instruments used in this study, as well as all other protocol procedures. * All females of child-bearing potential must test negative for pregnancy at Visit 1, based on a serum pregnancy test. Females of child-bearing potential (not surgically sterilised and between menarche and 1 year post-menopause) must agree to use a medically acceptable and reliable means of birth control (as determined by the investigator) during the study and for 1 month following the last dose of study drug. Examples of reliable methods include use of oral contraceptives or Depo Provera Contraceptive Injection, abstinence, partner with vasectomy, diaphragm with contraceptive jelly, condom with contraceptive foam, and intrauterine devices. Exclusion Criteria: * Have a known hypersensitivity to NSAIDs or strong opioids or any of the inactive ingredients or have any contraindication for the use of etoricoxib or oxycodone: * Patient with hypersensitivity to opioid analgesics; * acute asthma or other obstructive airway disease and acute respiratory depression with hypoxia; * elevated carbon dioxide levels in the blood; cor pulmonale; acute alcoholism; delirium tremens;severe CNS depression; convulsive disorders; increased cerebrospinal or intracranial pressure; * head injury; suspected surgical abdomen (paralytic ileus); concomitant MAO inhibitors (or within…