The medicine Oxaprozin is a non-steroidal, anti-inflammatory medicine and a derivative of propionic acid. The use of Oxaprozin may lead to increased risk of blood vessel problems and heart conditions. Oxaprozin medicine works by reducing the levels of chemicals in the body responsible for inflammation, pain and fever. It targets and blocks enzymes in the body that make prostaglandins. This action results in a reduction of pain, inflammation and fever.