Effect of rioprostil on aspirin-induced gastrointestinal mucosal changes in normal volunteers.

Rioprostil, a 15-deoxy-16-methyl prostaglandin E1, was evaluated for its effect on aspirin-induced gastrointestinal mucosal changes in normal volunteers. Fifty-six normal male volunteers were evaluated by endoscopy in a double-blind, placebo-controlled study. Aspirin was given at a dose of 975 mg four times per day. Rioprostil was given at doses of 60, 120, and 300 micrograms four times per day. Rioprostil, at both antisecretory and subantisecretory doses, prevented or reduced aspirin-induced injury. Increased stool frequency was the most common side effect and appeared to be a dose-related effect of rioprostil occurring at only antisecretory doses.