What is it?
The oral dose is 1–1.5 g (15–25 mg/kg) 2–3 times per day. I.V. dosage is typically 0.5–1 g by slow injection three times per day. Alternatively, the initial dose can be followed by an infusion of 25 – 50 mg/kg over 24 h. Dosing should be reduced to 5–10 mg kg IV in patients with renal failure.
The Lancet & Elsevier for the diagram of TXA interaction with respect to tissue injury
http://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(10)60939-7.pdf - Dr Jerrold Levy (@JerroldLevy)
TXA is used to treat or prevent excessive blood loss from trauma, surgery, and in various conditions including hAemophilia and heavy menstrual bleeding.
Dr. David Lyness
Synth. derivative of the AA, lysine and binds the 5 lysine binding sites on plasminogen.
This inhibits plasmin formation and displaces plasminogen from the fibrin surface.
Directly inhibit plasmin and partially inhibit fibrinogenolysis at higher concentrations.
Exerts an anti-inflammatory effect (by inhibiting plasmin-mediated activation of complement, monocytes, and neutrophils) and may improve platelet function in certain circumstances.
- No evidence for UGI bleeds
- Is used extensively in orthopaedic operations
- Reversal of drug-induced bleeding, like with dabigatran, rivaroxaban and LMWH's
- May improve platelet function and sometimes used post-cardiac surgery with such induced blood loss
- Oral surgery, by inhibiting fibrinolytic enzymes in saliva. MW or IV.
- ObGy - menorrhagia & new study is looking at PPH uses.
- Is used in cardiac surgery for blood loss
- Urology uses for haematuria, but can result in urinary clot retention
- Current studies looking into haemoptysis use - due to tPA action seen at pulmonary endothelium
- Liver/ENT/Max-Fax are currently awaiting cochrane review pubs.
- CRASH-2 & MATTERs trials show use in trauma patients - improving survival - it is hard to know how to translate findings --> surgery
Tranexamic acid may act as a competitive inhibitor of the central nervous system neurotransmitter GABA and it may also cause cerebral vasoconstriction and ischaemia.
Inhibits plasmin formation & displaces plasminogen, therefore preventing clot lysis.
Caution in those with renal failure
Caution in the elderly WRT dose & ?clot-risk
It has been hard to quantify actual risk of
thromboembolic events in those given
TXA. It is likely that a very large RCT would be
needed to power such conclusions.
Lack of evidence on optimal dosing regime
Acute traumatic coagulopathy is better defined now,
and so it is hard to translate this into a
surgical population outside CRASH-2
and the MATTERs trial.
Used with the intention of preventing bleeding
with good evidence in trauma and some good
evidence in some surgeries in reducing TRANSFUSION.
Blood transfusions are risky treatments
and it is best to prevent them. Could
TXA help with this?
Essential medication from WHO
Further work to be done on Cryoprecipitate (a rich source of fibrinogen) + TXA in bleeding/trauma patients.
Simplistically considered the opposite of tPA (alteplase)