Purpose: Osteoarthritis is a debilitating disease affecting a growing number of patients worldwide. It leads to progressive loss of cartilage, results in pain and loss of function. This obstructive pain response is the main reason for searching medical help and eventually choosing for joint replacement surgery. However, in many situations, especially in young patients, it is desirable to postpone joint replacement surgery as long as possible. Therefore, extensive research has been performed on new analgesics for treating OA joint pain.