Celebrex Celebrex Celebrex is a Non-Steroidal Anti-Inflammatory Drug (NSAID) that represents a huge breakthrough in the treatment of pain, inflammation, and stiffness of arthritis. * Celebrex is in a class of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). Celebrex works by reducing substances that cause inflammation, pain, and fever in the body. * Celebrex is used to reduce pain, inflammation, and stiffness caused by osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis. Celebrex is also used to reduce the number of adenomatous colorectal polyps in familial adenomatous polyposis (FAP), to treat acute pain, and to treat pain associated with menstruation. * Celebrex may also be used for purposes other than those listed in this medication guide. Take Celebrex exactly as directed by your doctor. If you do not understand these instructions, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose with a full glass of water.