Anti-inflammatory painkillers like mefenamic acid are sometimes called non-steroidal anti-inflammatory drugs (NSAIDs), or just 'anti-inflammatories'. Mefenamic acid is used to treat painful conditions such as arthritis, pain associated with heavy menstrual bleeding, and pain after surgical operations.
Mefenamic acid works by blocking the effect of chemicals called cyclo-oxygenase (COX) enzymes. These enzymes help to make other chemicals in the body, called prostaglandins. Some prostaglandins are produced at sites of injury or damage, and cause pain and inflammation. By blocking the effect of COX enzymes, fewer prostaglandins are produced, which means pain and inflammation are eased.