Study of Nonsteroidal Anti-inflammatory Drugs in People With Painful Knee Osteoarthritis

Inclusion Criteria: 1. Male or female \>40 years of age 2. Meet ACR criteria for knee OA 3. Able and willing to provide informed consent 4. Average weekly pain in the index knee based on daily pain assessments of ≥ 4/10 and \<9/10 on an 11-point NRS scale 5. Willing to discontinue current medications taken for OA pain 6. For women of child-bearing potential, willing to utilize some form of birth control or abstinence during the course of the study 7. If taking cannabinoids, have to be on a stable dose and have this maintained for the duration of the study 8. If receiving physical therapy or any non-pharmacologic modality(ies) for OA, these need to continue and remain stable for the duration of the study 9. Ambulatory 10. Have a cellphone and/or access to a computer and be able to utilize the eDiary as directed 11. Use of medications for knee OA pain on at least 4 out of 7 days per week 12. eDiary entries on at least 4 out 7 days per week during the observation period 13. Sub-Group Criterion (≥12 participants): Variability of average daily pain in the index knee during the observation period of ≥ 2 points on the NRS scale on at least 4 occasions Exclusion criteria: 1. History of intolerance or allergic reaction to NSAIDs 2. Previous history of GI bleed 3. Renal insufficiency resulting in serum creatinine \> 1.5 mg/dL 4. History of myocardial infarction in last 6 months 5. Coexisting congestive heart failure or symptomatic atherosclerotic heart disease 6. Use of oral anticoagulants other than aspirin ≤ 325 mg for cardiac prophylaxis 7. Use of heparin or injectable anticoagulant 8. Uncontrolled hypertension 9. Any medical condition which in the judgement of the investigator would make it inappropriate for the participant to enroll in the study 10. Use of recreational drugs 11. Fibromyalgia 12. Inflammatory arthropathies of any sort 13. Chronic back pain in which pain level is greater than the OA pain 14. Participation in another clinical trial other than one for covid or an observational and non-interventional study 15. Use of walker or other aid for walking other than a single cane 16. Hip pain on the ipsilateral side equal to or greater than the knee pain in the index joint 17. Index knee cannot have had previous joint replacement surgery 18. Arthroscopy within the past 6 months 19. Injection of hyaluronate in the index knee in the past 6 months 20. Corticosteroid injection in the index knee in the past 3 months 21. Injection of any biologic agent in the index in the past 12 months 22. Nerve ablation for the treatment of pain in the index knee 23. Any acute or chronic pain condition which would interfere with the evaluation of knee pain. 24. Pregnant, nursing or planning to become pregnant during length of study