Effect of aspirin on the human stomach in normals: endoscopic comparison of damage produced one hour, 24 hours, and 2 weeks after administration.

We studied the effects of regular aspirin on the human stomach by endoscopy in 15 volunteers divided equally into three groups. Each had a normal baseline endoscopy. In Group I, two aspirin or placebo tablets were administered suspended in 100 cc of water and endoscopic assessment made over on hour, at four hours, and 24 hours. In Group II, in a two way cross-over, blinded study we compared the effects of 24 hours' ingestion of 3.25 g of aspirin and placebo. Group III subjects received aspirin, two tablets four times daily for two weeks. In Group I, multiple petechiae (p less than 0.05) developed in the fundus and antrum by one hour and were still visible at 24 hours in 80%. In Group II, aspirin produced multiple antral erosions (p less than 0.05 vs. placebo) in all subjects and duodenal erosions in half. Antral and duodenal petechiae were common. In Group III, all subjects developed antral erosions (p less than 0.05 vs. control) and 50% duodenal erosions but only on subject developed petechiae. Acute aspirin administration appears to cause predominantly petechial hemorrhage in the fundus and antrum while longer term administration causes antral and duodenal erosions. Regular aspirin in recommended doses for one hour, 24 hours and two weeks produces endoscopically visible gastroduodenal damage in the majority of normal subjects.