Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) represent a remarkably frequently used class of drugs. The major motivation for the use of these drugs is the known gastrointestinal (GI) toxicity of aspirin. From premarketing studies it was known that NSAIDs could cause subclinical GI bleeding, but there were no controlled studies of the association between NSAID use and clinically apparent upper GI bleeding. In part because of the frequent use of these drugs and in part because of the potential seriousness of this adverse reaction, this association has been the subject of a considerable amount of postmarketing pharmacoepidemiology research. Despite this, many questions remain unanswered. This paper reviews the existing data on GI bleeding from NSAIDs and provides suggestions for future studies which could address some of the deficiencies in the data.