Pharmacodynamic properties
Etamsylate is a hemostatic and angioprotective drug that stimulates platelet adhesiveness shortening bleeding time and normalizing rapidly and lastly the altered vascular fragility and permeability. Its mechanism of action is attributed to the inhibition of prostacyclin (PGI2) synthesis that causes the platelet disaggregation, vasodilation and increase of capillary permeability and to the activation of P-selectine, which facilitates the interaction between platelets, leucocytes and endothelium. It acts on primary hemostasis without affecting prothrombin time, fibrinolysis or platelet count. In animal models of capillary bleeding, the administration of etamsylate shortens bleeding time and the severity of the hemorrhage up to 50% reaching its maximum effect between 30 minutes and 4 hours after its administration.

Pharmacokinetic particulars
In all the species studied, after an intravenous administration, etamsylate shows a limited tissue distribution, substantiated by a low Volume of Distribution (Vd: 0,4; 0,36 and 0.44 L/kg in dogs, cats and cattle respectively) due to its low liposolubility. Therefore, its action is practically limited to the circulatory system and blood vessels of highly irrigated organs. It is eliminated rapidly from the body with an elimination Half Life (T1/2) of 1,14; 0.75 and 1.24 h in dogs, cats and cattle, respectively, via urine, practically unaltered. When administered intramuscularly, etamsylate is absorbed very rapidly and almost completely (F: 97.5; 99.8 and 98.4 % in dogs, cats and cattle respectively). Etamsylate reaches the maximum blood concentrations (Cmax: 27; 25.8 and 10,7 µg/ml in dogs, cats and cattle respectively) approximately 1h after its administration (Tmax: 0.42; 0.54 and 1.3 h in dogs, cats and cattle respectively).