Hi & Welcome. I appreciate your concern for the safety of long term use of Azoran & Mesacol. Used as a maintenance treatment for inflammatory bowel disease like Ulcerative colitis, they are generally well tolerated. However the following side effects can occur on long term use. Azoran (Azathoprine) is an immunosuppressants and its side effect: Fever, chills , bone marrow depression resulting in decreased red blood cell, white blood cell and platelet counts which can cause anemia, increased risk of getting infections and bleeding tendency. Inflammation of the liver, rash or hair fall may also occur. Mesacol (Mesalamine) is an anti inflammatory drug and its side effects: Nausea, vomiting, abdominal cramps, constipation, allergic rash. In future if you develop sore throat, fever or cough it could be due to the decreased white blood cells caused by Azoran and you must report to the doctor immediately. Hope to have answered your query/.