naproxen and naproxen sodium, potent nonsteroidal anti-inflammatory drugs (NSAID) used to alleviate the minor pain of arthritis, menstruation, headaches, and the like, and to reduce fever. Along with ibuprofen and ketoprofen, they belong to the propionic acid class of NSAIDs. They have been available as prescription drugs for arthritis from 1976. Naproxen sodium was approved at a low dosage as an over-the-counter painkiller in the United States in 1994; it was first marketed under the tradename Aleve. Side effects may include gastrointestinal distress and dizziness, and renal impairment has been reported in some instances with long-term use. The drugs should not be used by those who are allergic to aspirin.