Gastritis, duodenitis, and bleeding duodenal ulcer following mefenamic acid therapy.

A 46-year-old woman developed hematemesis and melena two weeks after starting mefenamic acid therapy for osteoarthritis of the spine. Esophagogastroduodenoscopy, arteriography, and a laparotomy revealed antral gastritis, duodenitis, and an acute bleeding ulcer in the third portion of the duodenum. Although mefenamic acid has many of the pharmacologic and physicochemical properties of aspirin and produces gastrointestinal ulceration in animals when administered in large doses, the English literature reveals only one case of gastric ulceration and a single instance of upper-gastrointestinal tract hemorrhage associated with its use. This case warns that mefenamic acid may cause serious gastric and duodenal inflammation and ulceration more commonly than is presently suspected.