List of products in the National Drug Code with proprietary name . Naproxen is used to relieve pain from various conditions. It also reduces pain, swelling, and joint stiffness caused by arthritis, bursitis, and gout attacks. This medication is known as a nonsteroidal anti-inflammatory drug (NSAID). It works by blocking your body's production of certain natural substances that cause inflammation. If you are treating a chronic condition such as arthritis, ask your doctor about non-drug treatments and/or using other medications to treat your pain. See also Warning section. Some brands of sustained-release naproxen take longer to be absorbed and are not recommended for pain that needs quick relief (such as during a gout attack). Ask your doctor or pharmacist if you have questions about your particular brand.