NSAIDs, gastrointestinal injury, and cytoprotection.

Gastrointestinal toxicity caused by nonsteroidal anti-inflammatory drugs (NSAIDs) is the most frequent drug side effect in the United States. NSAIDs are implicated in the development of complicated peptic ulcer disease and injury to the small bowel and colon. NSAIDs interfere with prostaglandin-mediated epithelial defense mechanisms and also cause direct epithelial toxicity. Current and future approaches to the prevention and management of NSAID injury are reviewed.