Cimetidine and Tranexamic Acid for Upper-Gastrointestinal-Tract Bleeding

To the Editor: The article by Barer et al., “Cimetidine and Tranexamic Acid in the Treatment of Acute Upper-Gastrointestinal-Tract Bleeding,” (June 30 issue)* has one important omission. Whenever groups receiving two different therapies that probably work in different ways are being compared with a control group, the design should be a factorial one rather than the simple three-way comparison employed by the authors. If there had been one group receiving tranexamic acid, one group cimetidine, one group a placebo for both drugs, and one group both therapies, the question of interaction between the two drugs and the possibility that they.