Distribution of tranexamic acid to plasma and saliva after oral administration and mouth rinsing: a pharmacokinetic study.

The objective of the study was to investigate the content of tranexamic acid in plasma and in mixed, unstimulated whole saliva after oral administration and mouth rinsing. Ten healthy volunteers each received 1 g of tranexamic acid orally, whereas 20 healthy volunteers rinsed their mouths with 10 mL of a 5% aqueous tranexamic acid solution for two minutes. Blood and saliva were collected 30, 60, 120, 240, 360, and 480 minutes after administration of tranexamic acid. Samples of blood and saliva were analyzed for tranexamic acid content by electron capture gas chromatography. After oral administration, the mean plasma concentration of tranexamic acid reached its maximum after 120 minutes at approximately 7 micrograms/mL, whereas none of the saliva samples contained tranexamic acid at detectable levels. After mouth rinse, the plasma concentrations remained below 2 micrograms/mL, whereas the concentrations found in saliva initially were very high (after 30 minutes mean concentration above 200 micrograms/mL) and remained at a therapeutic level for more than two hours. These findings indicate, that fibrinolysis in the oral cavity can be inhibited only by local administration of tranexamic acid. This finding may be of significance when the drug is used for prevention and treatment of bleeding in the oral cavity in patients with coagulation defects.