Comparative study of gastrointestinal microbleeding caused by aspirin, fenbufen, and placebo

Fifty volunteers, randomly divided into five groups, received placebo, fenbufen, or aspirin at dosages used in treating osteoarthritis and rheumatoid arthritis (fenbufen, 600 or 900 mg daily; aspirin, 3.6 g daily) for 28 days. Following radioactive chromium labeling of red cells in each subject, stool specimens were collected weekly for determination of blood loss by radioisotope procedure. Statistical analyses demonstrated no significant differences in gastrointestinal microbleeding between subjects who received fenbufen (600 or 900 mg daily) and those who received placebo. Conversely, there were significant (p less than 0.01) differences in microbleeding between subjects given aspirin and those given either dosage of fenbufen or placebo.