Bleeding trauma patients do not die from blood loss alone. They die from a complex interaction of hemorrhage, shock, hypothermia, acidosis, coagulopathy, endothelial injury, and impaired clot stability.
Tranexamic acid targets one part of that physiology. It inhibits fibrinolysis.
To understand TXA, start with clot formation and clot breakdown. After vascular injury, the body forms clot to limit bleeding. At the same time, the fibrinolytic system prevents clot from spreading uncontrollably.
Plasmin breaks down fibrin. TXA inhibits activation of plasminogen to plasmin, helping preserve fibrin clot.
This is why timing matters.