title: Gastrointestinal microbleeding in normal subjects receiving acetylsalicylic acid, placebo, and R-803, a new antiinflammatory agent, in a design balanced for residual effects.
abstract: This study was undertaken to compare the relative gastrointestinal toxicity of equipotent doses of acetylsalicylic acid (ASA), 900 MG q.i.d., and a new anti-inflammatory agent, R-803, 300 mg q.i.d., against placebo. Gastrointestinal micro-bleeding was quantitated with the 61Cr-labeled erythrocyte assay. The experimental design was balanced for residual effects in the first week following any treatment. An interesting relationship between stool weight and blood loss was found to influence the microbleeding independently of the treatments themselves. All observed blood loss values were corrected by regression to a reference stool weight of 100 Gm. Final analysis of corrected values was done on arithmetic and logarithmic scales. On both scales, R-803 induced much less blood loss than ASA. A difference of 1.3 ml/day between R-803 and placebo was not statistically significant on the arithmetic scale. On the log scale, a statistically significant difference was found; but since it corresponds to 0.4 ml/day, it was not considered to be clinically significant at this dosage.
mesh_terms: D000893:Anti-Inflammatory Agents / Q000009:adverse effects*; D001241:Aspirin / Q000009:adverse effects*; D001572:Benzofurans / Q000009:adverse effects*; D002860:Chromium Radioisotopes; D005243:Feces; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced*; D006801:Humans; D008297:Male; D010919:Placebos
chemical_list: D000893:Anti-Inflammatory Agents; D001572:Benzofurans; D002860:Chromium Radioisotopes; D010919:Placebos; D001241:Aspirin