KF 13218 is a potent, selective and long lasting thromboxane B2 (TXB2) synthase inhibitor with an IC50 value of 5.3±1.3 nM.

KF 13218 inhibits human and bovine platelet thromboxane synthase with IC50 values of 27±5.8 nM (mean±S.E.M.) and 36±6.9 nM, respectively. KF 13218 does not inhibit cyclooxygenase or 5-lipoxygenase up to a dose of 100 μM and does not antagonize thromboxane A2/prostaglandin H2 receptors. KF 13218 inhibits arachidonic acid-induced thromboxane B2 production by human intact platelets with an IC50 value of 5.3±1.3 nM. The IC50 value of KF 13218 for the intact platelets is about 5 times lower than that for the microsomal enzyme. The inhibition of thromboxane synthase in platelets by KF 13218 is sustained after removal of the extracellular compound[1].

After oral dosing in rat from 0.03 mg/kg to 3 mg/kg, KF 13218 dose-dependently inhibits the thromboxane B2 production in serum, and the inhibition is retained for 72 h. KF 13218, at a dose of 0.1 mg/kg p.o. prevents mortality induced by sodium arachidonate in rabbit[1].

[1]. Miki I, et al. A novel pyridobenzazepinone derivative with long lasting thromboxane synthase inhibition. Arzneimittelforschung. 1995 Oct;45(10):1066-70.