Tranexamic Acid
Chemical
A synthetic analogue of LYSINE
WHO’s list of essential medicines
(the most effective & safe medicines needed in a health system)
Use
- Cardiac sx (↓peri-op bleeding)
- Reverse thrombolytic therapy
- Menorrhagia
- Dental bleeding
- Epistaxis
- Haemoptysis
- Haemorrhagic shock (Trauma, Obs + surgical haemorrhage)
- DIC
Presentation
Tablets 500mg
Vials
- 5000mg/50mL
- 1000mg/10mL
- 500mg/5mL
Dose
Menorrhagia: PO 1g QID
IV 20mg/kg over 5 mins
Trauma/haemorrhage: IV 1g over 10min (IV) → 1g IV over 8hrs
Epistaxis → topical
Mouthwash → 10mL 5%
Dose adjust in ↓renal impairment
Route
PO/IV
Onset
5 – 15 mins → DoA 3hrs
MoA (mechanism)
- Binds plasminogen lysine binding sites (REVERSIBLE)
- Competitively inhibits activation of plasminogen → plasmin
- ∴stops fibrinolysis
- 10 x stronger than aminocaproeic acid
- At v. high doses inhibits PLASMIN
PD
(systems)s
PK
A
OBA 34%
D
3% PPB because binds almost exclusively to plasminogen
M
Minimal
E
Urine
95% unchanged
t ½ 2 – 11hrs
Adverse Effects
Ocular – vision ∆
Seizures
Renal impairment
Pulmonary Hypertension
Hypotension with rapid administration
GI disturbance (PO) → N&V, diarrhoea, GORD
Intravascular thrombosis (largely theoretical); no consistent data that shows increased risk of thrombosis with its use
- Discovered by Utako Okamoto in 1950s
… who was looking for a drug to treat PPH - She could not persuade Kobe obstetricians to use it… however eventually made its way to the WHO essential medicine list!