Piroxicam is in a class of medications called NSAIDs. It works by stopping the body’s production of a substance that causes pain, fever, and inflammation. Piroxicam is used to relieve pain, tenderness, swelling, and stiffness caused by osteoarthritis (arthritis caused by a breakdown of the lining of the joints) and rheumatoid arthritis (arthritis caused by swelling of the lining of the joints).