Tolmetin sodium is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits prostaglandin synthetase in vitro and reduces plasma levels of prostaglandin E. Tolmetin sodium exhibits anti-inflammatory, analgesic and antipyretic activity Its precise mechanism of is unknown. Tolmetin is used to treat rheumatoid arthritis, osteoarthrosis, pain, and ankylosing spondylitis.