Oxaprozin, also known as oxaprozinum, is a nonsteroidal anti-inflammatory drug (NSAID), used to relieve the inflammation, swelling, stiffness, and joint pain associated with osteoarthritis and rheumatoid arthritis. Chemically, it is a propionic acid derivative. Safety and efficacy has been established in children over 6 years with juvenile rheumatoid arthritis only, and there is an increased risk of adverse reactions in the elderly population.