Aspirin‐Induced Occult Gastrointestinal Blood Loss: Local Versus Systemic Effects

Abstract

The purpose of this study was to determine if occult gastrointestinal blood loss produced by therapeutic doses of aspirin in man is a local or systemic effect. The daily oral administration of from 3.9 to 5.2 g. aspirin in tablets for 8 days increased the average daily blood loss from 0.3 to 6.4 ml. in nine normal subjects. Intravenous administration of from 2.7 to 3.4 g. Aspirin as the sodium salt per day for 3 days to the same subjects caused no measurable gastrointestinal blood loss above control values. The average bleeding time increased from a control value of 2.6 to 4.5 min. during oral aspirin administration and to 4.1 min. during intravenous administration of the drug. The absence of gastrointestinal bleeding due to intravenous aspirin and the similarity in the degree of prolongation of bleeding time by both oral and intravenous aspirin indicate that gastrointestinal bleeding is a local effect of the drug and is not related to changes in the bleeding time.