FR-188582 inhibits COX-2 (IC50: 17 nM), in a recombinant human COX enzyme activity. The inhibition of prostaglandin (PG) E2 formation by FR188582 is over 6000 times more selective for COX-2 than COX-1.

FR-188582 (0.01-3.2 mg/kg, p.o.) reverses paw edema in adjuvant arthritic rats and displays a therapeutic effect in a dose-dependent manner. For adjuvant-injected paws and adjuvant-uninjected paws, the ED50s values (95% C.L.) are 0.074 (0.00021-0.53) and 0.063 (0.0039-0.31) mg/kg , respectively. The anti-inflammatory effect of FR-188582 is threefold more potent than that of Indomethacin. For adjuvant-injected paws and adjuvant-uninjected paws, the ED50s values (95% C.L.) are 0.24 (0.047-1.8) and 0.20 (0.021-0.79) mg/kg, respectively.