Any nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation by inhibiting cyclooxygenase-2 (COX-2) but not cyclooxygenase- 1 (COX-1). Most NSAIDs (e.g., celecoxib) inhibit both COX-2 and COX-1. Selective inhibition prevents the coxibs from forming prostaglandins, which irritate the upper gastrointestinal tract.