Naproxen 500 mg pills. Brand names: Anaprox, Naprelan, Naprosyn, Aleve. Naproxen belongs to a class of drugs called non-steroidal anti-inflammatory drugs (NSAID). Other members of this class include ibuprofen (Motrin), indomethacin (Indocin), nabumetone (Relafen) and several others. These drugs are used for the management of mild to moderate pain, fever, and inflammation. They work by reducing the levels of prostaglandins, chemicals that are responsible for pain, fever and inflammation. Naproxen blocks cyclooxygenase, the enzyme that makes prostaglandins, resulting in lower concentrations of prostaglandins. As a consequence, inflammation, pain, and fever are reduced.