Tranexamic Acid is a synthetic derivative of the amino acid lysine with antifibrinolytic activity. With a strong affinity for the five lysine-binding sites of plasminogen, tranexamic acid competitively inhibits the activation of plasminogen to plasmin, resulting in inhibition of fibrinolysis; at higher concentrations, this agent noncompetitively inhibits plasmin. This agent has a longer half-life, is approximately ten times more potent, and is less toxic than aminocaproic acid, which possesses similar mechanisms of action.
Tranexamic acid belongs to the class of medications called antifibrinolytic agents. This medication is used to prevent or reduce bleeding in certain conditions, such as dental surgery in people with hereditary blood clotting disorders, cervical surgery, heavy menstrual bleeding, nosebleeds and bleeding inside the eye.
Mechanism of Action of Tranexamic acid
Tranexamic acid competitively inhibits activation of plasminogen (via binding to the kringle domain), thereby reducing the conversion of plasminogen to plasmin (fibrinolysin), an enzyme that degrades fibrin clots, fibrinogen, and other plasma proteins, including the procoagulant factors V and VIII. Tranexamic acid also directly inhibits plasmin activity, but higher doses are required than are needed to reduce plasmin formation. Tranexamic acid is a synthetic analog of the amino acid lysine. It serves as an antifibrinolytic by reversibly binding four to five lysine receptor sites on plasminogen or plasmin. This prevents plasmin (antiplasmin) from binding to and degrading fibrin and preserves the framework of fibrin’s matrix structure. Tranexamic acid has roughly eight times the antifibrinolytic activity of an older analog, ε-aminocaproic acid.
Indications of Tranexamic Acid
- Hemorrhage
- Hereditary angioedema
- Chronic heavy menstrual bleeding
- In hereditary angioedema
- In hereditary hemorrhagic telangiectasia – Tranexamic acid has been shown to reduce the frequency of epistaxis in patients suffering severe and frequent nosebleed episodes from hereditary hemorrhagic telangiectasia.
- In melasma – tranexamic acid is sometimes used in skin whitening as a topical agent, injected into a lesion, or taken by mouth, both alone and as an adjunct to laser therapy; as of 2017 its safety seemed reasonable but its efficacy for this purpose was uncertain because there had been no large scale randomized controlled studies nor long term follow-up studies.
- In hyphema – Tranexamic acid has been shown to be effective in reducing the risk of secondary hemorrhage outcomes in patients with traumatic hyphema.
- For beautification – someone uses the tranexamic acid for extra beautification
- Prostatectomy and bladder surgery
- Menorrhagia
- Epistaxis
- Conisation of the cervix
- Traumatic hyphaema
- Management of dental extraction in hemophiliacs.
- Hereditary angioneurotic edema.
- For use in patients with hemophilia for short-term use (two to eight days) to reduce or prevent hemorrhage and reduce the need for replacement therapy during and following tooth extraction. It can also be used for excessive bleeding in menstruation, surgery, or trauma cases.
Contra-Indications of Tranexamic Acid
- Abnormal Increase in the ability of blood to clot
- Fluid accumulation in the brain
- Retinal thrombosis
- Heart attack
- Acute blood clot in a blood vessel supplying the lungs
- Heart valve disease
- Subarachnoid intracranial hemorrhage
- The blood clot in the brain
- Stroke
- Obstruction of a blood vessel by a blood clot
- Blood clot
- A blood clot in a deep vein of the extremities
- Moderate to severe kidney impairment
- Chronic degenerative conjunctivitis with fibrin deposits
- Allergies to tranexamic acid
Dosages of Tranexamic Acid
Strengths: 500 mg; 650 mg; 100 mg/mL;
Bleeding
For the treatment of cyclic heavy menstrual bleeding
- 1,300 mg (two 650 mg tablets) orally three times a day (3,900 mg/day) for a maximum of 5 days during monthly menstruation.
For patients with hemophilia for short-term use (two to eight days) to reduce or prevent hemorrhage and reduce the need for replacement therapy during and following tooth extraction
- Immediately before dental extraction in patients with hemophilia, administer 10 mg per kg body weight intravenously. Following surgery, a dose of 10 mg per kg body weight intravenously three to four times daily, may be used for 2 to 8 days.
Pediatric Dose for Bleeding
Immediately before dental extraction: 10 mg per kg body weight intravenously
- Following surgery: 10 mg per kg body weight intravenously three to four times daily, may be used for 2 to 8 days.
Surgery for congenital heart disease (to reduce perioperative blood loss and need for transfusions)
2 months to 15 years
- loading dose: 100 mg/kg intravenously, followed by 10 mg/kg/hour infusion (continued until ICU transport) and 100 mg/kg priming dose when bypass initiated; or
- loading dose: 10 mg/kg intravenously, priming dose: 10 mg/kg and 10 mg/kg after protamine.
Surgery for scoliosis (to reduce perioperative blood loss and need for transfusions)
8 to 18 years
- loading dose: 100 mg/kg intravenously, followed by infusion: 10 mg/kg/hour until skin closure
- loading dose: 20 mg/kg intravenously, followed by 10 mg/kg/hour infusion
- loading dose: 10 mg/kg intravenously and 1 mg/kg/hour infusion.
For the treatment of cyclic heavy menstrual bleeding (ages 12 to less than 18)
- 1,300 mg (two 650 mg tablets) orally three times a day (3,900 mg/day) for a maximum of 5 days during monthly menstruation.
Side Effects of Tranexamic Acid
The most common
- a mild headache;
- runny or stuffy nose;
- stomach pain;
- tired feeling;
- eye redness; or
- back pain, joint or muscle pain.
- problems with your vision (including color vision);
- sudden numbness or weakness, especially on one side of the body;
- sudden headache, confusion, problems with vision, speech, or balance;
- sudden chest pain or trouble breathing;
- pain or swelling in one or both legs;
- migraine headache;
- pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating; or
- feeling like you might pass out.
More common
- Abdominal or stomach pain, discomfort, or tenderness
- chills or fever
- difficulty with moving
- headache, severe and throbbing
- joint or back pain
- muscle aching or cramping
- muscle pains or stiffness
- stuffy or runny nose
- Pale skin
- trouble breathing with exertion
- unusual bleeding or bruising
- unusual tiredness or weakness
Incidence not known
- Anxiety
- change in vision
- chest pain or tightness
- confusion
- cough
- difficulty with swallowing
- dizziness or lightheadedness
- fainting
- fast heartbeat
- numbness of the hands
- pain, redness, or swelling in the arm or leg
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
Drug Interactions of Tranexamic Acid
There may be an interaction between tranexamic acid and any of the following:
- fibrinogen
- hormonal birth control (estrogens and progesterone)
- tretinoin
Some products that may interact with this drug include: “blood thinners” (anticoagulants such as warfarin, heparin), drugs that prevent bleeding (including factor IX complex, anti-inhibitor coagulant concentrates), tretinoin, estrogens, hormonal birth control (such as pills, patch, ring).
Check all prescription and nonprescription medicine labels carefully since many medications contain pain relievers/fever reducers (NSAIDs such as aspirin, ibuprofen, naproxen) that may increase your risk of bleeding. Low-dose aspirin should be continued if prescribed by your doctor for specific medical reasons such as heart attack or stroke prevention (usually at dosages of 81-325 milligrams per day). Ask your doctor or pharmacist for more details.
Pregnancy & Lactation
FDA Pregnancy Category B
Pregnancy
This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Lactation
This medication passes into breast milk in very small amounts. If you breastfeeding mother and are taking tranexamic acid, it may affect your baby. Research has shown that it is probably safe for the baby to breast feed while you are taking this medication, however you may wish to talk to your doctor about whether you should continue breast-feeding.
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