Tranexamic acid
Trans-4- (aminomethyl ) cyclohexane-1 -carboxylic acid
B02AA02
Beige solid
Fibrinolysis inhibitor
Lysine analog
386-392 ° C ( decomposition)
- Well in water
- Poorly in ethanol and diethyl ether
Attention
1200 mg · kg -1 ( LD50, rat, i.v.)
Template: Infobox chemical / molecular formula search available
Tranexamic acid is a substance which is used in medicine for the inhibition of the fibrinolytic system. The mechanism of action is based on a complex formation with plasminogen, thus its binding is inhibited at the fibrin surface. This ultimately results in an inhibition of clot dissolution ( fibrinolysis ). It is therefore referred to as anti-fibrinolytic ( Fibrinolysehemmer ).
Origin and production
Tranexamic acid is a synthetic material similar to that of lysine. It counts as ε - aminocaproic acid and p- aminomethyl benzoic acid to the group of so-called ε -amino carboxylic acids.
Mechanism of action
Tranexamic acid blocks the formation of plasmin, by inhibition of the proteolytic activity of the plasminogen activators. This plasmin is inhibited to lyse fibrin in his ability. At low dose tranexamic acid acts as a competitive inhibitor of plasmin, at high doses as a non- competitive inhibitor. All ε -amino carboxylic acids have the same effect.
Pharmacokinetics
Absorption and bioavailability
Tranexamic acid is bioavailable after oral administration to 30-50 %. Volume of distribution of 9-12 L. The half-life is 2 hours.
Metabolism
Tranexamic acid is only slightly metabolized in the liver. As metabolites to carboxylic acid have let (1 % of the administered dose), and the acetylated form of tranexamic acid ( 0.1 % of the administered dose) find in the urine.
Excretion
Excretion is 95% through the kidneys and urinary tract ( renal elimination ). Due to the almost exclusively renal elimination of the substance, the dose must be reduced in renal failure, especially with prolonged use, so that no accumulation of tranexamic acid in the plasma is. As a function of creatinine in serum, the number of doses per day is reduced.
Interactions
Case of joint administration of tranexamic acid and factor IX increased risk of thrombosis is observed.
Areas of application
- For the prevention or amelioration of bleeding in tooth extraction or gingival bleeding in hemophilia.
- Generalized and / or local fibrinolysis. Reduction of fibrinolysis caused either by excess of plasmin ( Hyperplasminämie ) or as a result of thrombolytic therapy with streptokinase for example. An increased local fibrinolysis may occur in prostate surgery and surgery on the urinary tract in recurrent bleeding of the gastrointestinal tract, ulcerative colitis, in essential or IUD- induced Menorrhagia (increased menstrual bleeding ), with epistaxis and after tooth extraction in patients with coagulation disorders ( coagulopathy ). Likewise, tranexamic acid is used during operations with extracorporeal circulation (heart -lung machine ).
- Tranexamic acid is used as an antidote ( remedy) with the blocking of fibrinolytic agents such as streptokinase another application. Alternatively, it was also the proteinase inhibitor ( antiplasmin ) aprotinin was withdrawn from the market because of its thrombogenic effect.
- Hereditary angioedema (HAE ).
Side effects
- Hypersensitivity reactions are both systemic ( whole body ) and in the form of rashes before.
- Tranexamic acid may occur especially in patients with congenital or acquired tendency to thrombosis ( thrombophilia ) lead to the formation or propagation of thrombosis. Thrombosis may subsequently lead to embolism ( pulmonary embolism, stroke).
- Atrial fibrillation with increased risk for stroke.
- Tranexamic acid may cause vision problems in people. In animal experiments, retinal damage have been reported.
Contraindications ( contraindications)
- Lactation. Tranexamic acid is excreted in human milk ( very low concentrations ).
- Bleeding in the urinary tract. It can be caused by application of tranexamic acid blockages of the ureter with subsequent Urinaufstau.
- Thrombosis. Thrombosis ( pre-existing ) should be promoted with the administration of tranexamic acid.
- Sepsis and DIC (disseminated intravascular coagulation ).
Dosage forms and dosage strengths
Trade names
Cyklokapron, Manufacturer: MEDA Pharma; Quixil Manufacturer: OMRIX biopharmaceuticals