Classification of NSAIDs based on the mode of action.

Class	Properties	Examples
Group I	Non-selective weak inhibitors of COX	5-Aminosalicylic acid, sodium salicylate, nabumetone, sulfasalazine
Group II	Non-selective strong inhibitors of COX	Diclofenac, ibuprofen, ketoprofen, flurbiprofen, indomethacin, piroxicam, naproxen, aspirin
Group III	Preferential COX-2 inhibitor with 5–50 fold selectivity	Celecoxib, etodolac, meloxicam, nimesulide
Group IV	Preferential COX-2 inhibitor with >50-fold selectivity	Rofecoxib