Outcome trials of COX-2 selective inhibitors: global safety evaluation does not promise benefits.

Background: Gastrointestinal toxicity is the most frequent adverse effect associated with nonsteroidal anti-inflammatory drug use. The most clinically relevant side effects of this toxicity are ulcer complications, including perforation, obstruction, or bleeding. Selective cyclooxygenase (COX-2) inhibitors (coxibs) have been proposed as a safer alternative to traditional, nonsteroidal anti-inflammatory drugs and they are currently widely used in clinical practice.