Indomethacin is a potent and nonselective inhibitor of COX1 and COX2 , with IC ₅₀ s of 18 nM and 26 nM for human COX-1 and COX-2, respectively, in CHO cells. Indomethacin inhibits lipopolysaccharide (LPS)-induced PGE2 production (COX-2) in a human whole blood assay with a potency (IC ₅₀ =0.68±0.17?μM), and suppresses coagulation-induced TXB2 production (COX-1) (IC ₅₀ =0.19±0.02?μM). Indomethacin blocks COX-1 with an IC ₅₀ of 20±1?nM in U937 cell microsomes at a low arachidonic acid concentration (0.1?μM).

Indomethacin dose-dependently inhibits both the carrageenan-induced rat paw oedema (ED ₅₀ , 2.0?mg/kg), hyperalgesia (ED ₅₀ , 1.5?mg/kg), and is also effective at reversing LPS-induced pyrexia in rats (ED ₅₀ , 1.1?mg/kg). Indomethacin (2.5 mg/kg, i.p) decreases the number of NeuN ⁺ cells in the animals at 8 days after ET-1 injection. Indomethacin also reduces microglia/macrophage activation at 14 days. Indomethacin significantly increases the number of SVZ DCX ⁺ cells/field at 14 days post stroke. Indomethacin (22.9 mg/kg, p.o.) produces 8 to 10 linear mucosal lesions extended from the fundic to pyloric area of stomach wall.