止血劑 (haemostatic) Antiplasmin (antifibrinolytic) agent. Used in haemorrhage caused by administration of plasminogen activators (streptokinase, urokinase), obstetric complications, and in hyperplasminaemic states.

Tranexamic acid is a competitive inhibitor of plasminogen activation, and at much higher concentrations, a noncompetitive inhibitor of plasmin, i.e., actions similar to aminocaproic acid.

The plasma protein binding of tranexamic acid is about 3% at therapeutic plasma levels and seems to be fully accounted for by its binding to plasminogen. Tranexamic acid does not bind to serum albumin. After an intravenous dose of 1 g, the plasma concentration time curve shows a triexponential decay with a half-life of about 2 hours for the terminal elimination phase. The initial volume of distribution is about 9 to 12 liters. Urinary excretion is the main route of elimination via glomerular filtration. Overall renal clearance is equal to overall plasma clearance (110 to 116 mL/min), and more than 95% of the dose is excreted in the urine as unchanged drug. Excretion of tranexamic acid is about 90% at 24 hours after intravenous administration of 10 mg per kg body weight. An antifibrinolytic concentration of tranexamic acid remains in different tissues for about 17 hours, and in the serum, up to seven or eight hours.

Active intravascular clotting process, acquired defective color vision, subarachnoid hemorrhage, hypersensitivity to tranexamic acid.

B

Tranexamic acid should be used during lactation only if clearly needed.

Diarrhea, headache, hypotension, heartburn, dizziness, pruritus, erythema, skin rash , nausea, nasal stuffiness, diuresis, muscle pain, weakness, intrarenal obstruction.

IV, usual dose is 0.5 to 1g (10 to 15mg/kg) given 2 to 3 times daily

Dosage adjustment in renal impairment (IV):
SCr 1.36 to 2.83 mg/dL, 10 mg/kg IV Q12H
SCr 2.83 to 5.66 mg/dL, 10 mg/kg IV Q24H
SCr greater than 5.66 mg/dL, 10 mg/kg IV Q48H or 5 mg/kg IV Q24H