List of products in the National Drug Code with proprietary name . This medication is used to reduce pain and swelling due to certain types of arthritis (such as rheumatoid, psoriatic, and ankylosing spondylitis). It works by blocking a protein (tumor necrosis factor or TNF) found in the body's immune system that causes joint swelling and damage. By reducing joint swelling, the medication helps to reduce further joint damage and preserve joint function. Depending on the type of arthritis that is being treated, this drug may be used alone or in combination with another drug called methotrexate. This medication is also used to treat a certain bowel condition (ulcerative colitis). It is used to help lessen symptoms of moderate to severe ulcerative colitis (such as abdominal pain/cramping, diarrhea, bloody stools).