Selectivity and specificity of Cox-inhibitors (Lipsky et al, Editorial, J. Rheumatol, 1998, 25, 2298-2303)
Levels 1 & 2, Selectivity
1. Enzymatic or biochemical - in vitro COX-1/COX- 2 ratio
2. Biological and pharmacologic - ex-vivo cell assays
Level 3, Clinical specificity
3. At fully efficacious therapeutic concentration
- No inhibition of COX-1 mediated platelet function
- No clinically relevant COX-1 inhibitory effect on GI tract
= COX-2 SPECIFIC INHIBITION (CSI)