Relative COX-1 and COX-2 selectivity of NSAIDs

Concentrations of various NSAIDs required to inhibit the activity of COX-1 and COX-2 by 50% (IC50) in assays of whole blood. The diagonal line indicates equivalence. Drugs plotted below the diagonal line indicating equivalence are more potent inhibitors of COX-2 relative to COX-1 than drugs plotted on or above the line.