Patient case (clinical description): A 47-year-old woman comes to the office complaining of pain in the calf and knee when she bends down. The pain limits her activity. Her medical history is significant for osteoarthritis, for which she uses nonsteroidal anti-inflammatory drugs (NSAIDs) for the past two years. She is living with her husband and has 3 children. She doesn't smoke but drinks alcohol occasionally. Her vital signs are normal. On physical examination, there is a small effusion in the right knee. The effusion grew a little larger and she developed a tender swelling in the popliteal fossa and calf. Both the pain and swelling worsened as she bent and straightened her knee.

Patient's own account: I'm a 47-year-old woman, married with 3 kids. I don't smoke and I drink occasionally. I went to the doctor because of pain in my calf and knee when I was bending down. This has been limiting my daily activities. I have been diagnosed with osteoarthritis for which I have taken anti-inflammatory drugs for the past 2 years. The doctor saw a small fluid buildup in my right knee. This buildup became a bit bigger and I have a swollen calf. The pain is worse when I bend and straighten my knee.

Clinical trial: Bioequivalence Study With Clinical Endpoint for Diclofenac Sodium Topical Gel 1%

Eligibility criteria:
Inclusion Criteria:

          1. Ambulatory male and non-pregnant females 35 years and older diagnosed with
             osteoarthritis according to the American College of Rheumatology Criteria (ACR) in one
             knee. Target knee is the one with higher level of pain.

             ACR Criteria includes: Knee Pain and at least 3 of the following: age ≥ 50, stiffness
             lasting < 30 mins, bony tenderness, crepitus, bony enlargement, and no palpable
             warmth.

          2. Symptom onset of > 6 Months prior to Screening for the target knee.

          3. If female and of child-bearing potential, prepare to abstain from sexual intercourse
             or use a reliable method of contraception during the study (e.g., IUD, oral,
             transdermal, injected, implanted hormonal contraceptives or condom + spermicide).

          4. Periarticular knee pain due to osteoarthritis (not bursitis, tendonitis etc.) that
             required the use of oral or topical treatments (e.g., NSAIDs or acetaminophen).

          5. Radiograph of the target knee within the previous year with a Grade 1, 2 or 3 disease
             based upon the Kellgren-Lawrence disease severity scale.

          6. After a minimum of 7-day wash out of all pain medication has Baseline pain on movement
             score of ≥ 50mm on a 0-100-mm Visual Analogue Scale for the target knee.

          7. After a minimum of 7-day wash out of all pain medication has Baseline WOMAC Pain sub
             scale of ≥ 9 on a 5 question, 5 point (0 to 4) Likert scale for the target knee.

          8. Willing and able to use only acetaminophen as rescue medication.

          9. Willing and able to comply with the study requirements.

        Exclusion Criteria:

          1. Females who are pregnant, breast feeding, or planning a pregnancy.

          2. Radiograph of the target knee within the previous year with a Grade 4 score on the
             Kellgren-Lawrence disease severity scale.

          3. History of osteoarthritis in the contralateral knee requiring medication (OTC or
             prescription) within 12 months of screening.

          4. After a minimum of 7-day wash out of all pain medication has Baseline pain on movement
             score of ≥ 20mm on a 0-100-mm Visual Analogue Scale for the contralateral knee
             immediately prior to randomization.

          5. Known history of secondary osteoarthritis (e.g. congenital, traumatic, gouty
             arthritis) of the knee or rheumatoid arthritis.

          6. Known history of other chronic inflammatory diseases, (e.g., colitis) or fibromyalgia
             during last 5 years. Patients whose disease was diagnosed at least 5 (five) years
             prior to screening visit and have had no known disease activity (i.e., no disease
             related complaints nor disease treatment prescribed) since then may enter into the
             study.

          7. History of asthma, hypertension, myocardial infarction, thrombotic events, stroke,
             congestive heart failure, impaired renal function or liver disease. Patients who have
             had high blood pressure measured at least 2 (two) years prior to screening visit and
             have had no disease activity (i.e., no record of hypertension or anti-hypertensive
             treatment prescribed) for at least 2 (two) years prior to screening visit may enter
             into the study.

          8. History of coronary artery bypass graft within 6 months of screening.

          9. Concomitant acetylsalicylic acid therapy other than a stable low dose used for cardiac
             prophylaxis (max. 162 mg daily) taken for at least 3 months prior to enrollment and
             maintained throughout the duration of the study.

         10. Use of warfarin or other anticoagulant therapy within 30 days of screening.

         11. Use of ACE inhibitors, cyclosporine, diuretics, lithium or methotrexate, within 30
             days of screening or during the study.

         12. Known history of gastrointestinal bleeding or peptic ulcer disease.

         13. Abnormal screening clinical laboratory evaluations which the Investigator deems
             clinically significant.

         14. Known allergy to aspirin or NSAIDs.

         15. Skin lesions or wounds in the affected area.

         16. Significant (requiring surgery) injury or major knee surgery to either knee within six
             months prior to screening.

         17. Transaminase levels that are more than two times the upper limit of the normal range
             at screening.

         18. Any other acute or chronic illness that in the opinion of the investigator could
             compromise the integrity of study data or place the Patient at risk by participating
             in the study.

         19. Concomitant use of corticosteroids (any formulation) or use within 30 days of study
             randomization.

         20. Receipt of any drug as part of a research study within 30 days prior to screening.

         21. Previous randomization into this study.

         22. Known allergy (hypersensitivity) to acetaminophen.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 35 Years old.


Eligibility (NLI label): Entailment