Trial to See if Topical Pennsaid for Knee Pain Affects Coagulation Values in Patients Who Are Also Taking Anticoagulants

Inclusion Criteria

• Male or female adults > than or equal to 55
• Ambulatory subjects with moderate to severe osteoarthritis (OA) of the knee with symptoms and knee pain for at least 3 months and pain on the majority of days in the last 30 days.
• Subjects with bilateral knee OA, the more symptomatic knee is the index knee and PENNSAID can be applied on both knees if both are affected.
• Radiographic evidence of Kellgren-Lawrence Grade 2-4 within the past 2 years.
• Currently on a stable dose of anticoagulant therapy (warfarin, dabigatran, aspirin or clopidogrel) for the past 2 months and expected to remain on current dose for the six week duration of the study.
• If currently taking oral nonsteroidal antiinflammatory drug (NSAID) and/or acetaminophen for OA knee pain, must be taking it for at least an average of 25 days per month.
• Those currently taking oral NSAID must be willing to perform a 7 day washout to be eligible to be enrolled into the study.
• A pain score of > than 40mm on the Patient Pain Visual Analog Scale (VAS) (100 mm scale) at screening and baseline visit.
• Able to comply with the study and give informed consent prior to performance of any study procedures.
• Able to read, write and understand English.

Exclusion Criteria

• Unwilling to abstain from oral NSAIDs and/or other analgesic medication except for acetaminophen as rescue medication. Subjects taking low dose aspirin for cardiovascular health may remain on their stable dose throughout the study.
• Unwilling to abstain from taking than or equal to 50% of the time.
• Undergoing new physical therapy or participating in a weight loss or exercise program that has not been stable for at least 3 months prior to screening and won't remain stable during participation in study.
• History or diagnosis of an inflammatory arthritis i.e. rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, arthritis associated with inflammatory bowel disease, sarcoidosis, or amyloidosis.
• Known or clinically suspected infection and human immunodeficiency virus (HIV), or hepatitis C or B viruses.
• History of abnormal laboratory results > that or equal to 2.5 x upper limit of normal (ULN) indicative of any significant medical disease which in the opinion of the investigator, would preclude the subjects participation in the study.
• Any of the following abnormal laboratory results during screening:
• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) > than or equal to 2.5 x ULN
• Hemoglobin than or equal 1.5 x ULN
• Platelet count below the central laboratory lower limit of normal (LLN)
• Coagulation tests (Prothrombin Time (PT), Partial Thromboplastin Time (PTT), International Normalized Ratio (INR), Platelet Aggregation) requiring an alteration in anticoagulant dosage.
• Skin breakdown or rash at knee where topical PENNSAID is to be applied.
• Other serious uncontrolled non-malignant, significant, acute or chronic medical or psychiatric illness that, in judgment of investigator, could compromise subject safety, limit subject's ability to complete study and/or compromise the objectives of study.
• History of malignancy in the past 5 years with exception of resected basal cell carcinoma, squamous cell carcinoma of the skin, or resected cervical atypia or carcinoma in situ.
• History of drug or alcohol dependence or abuse in the past 3 years.