Tranexamic acid

12.1 Mechanism of Action Tranexamic acid is a synthetic lysine amino acid derivative, which diminishes the dissolution of hemostatic fibrin by plasmin. In the presence of tranexamic acid, the lysine receptor binding sites of plasmin for fibrin are occupied, preventing binding to fibrin monomers, thus preserving and stabilizing fibrin's matrix structure. The antifibrinolytic effects of tranexamic acid are mediated by reversible interactions at multiple binding sites within plasminogen. Native human plasminogen contains 4 to 5 lysine binding sites with low affinity for tranexamic acid (Kd = 750 μmol/L) and 1 with high affinity (Kd = 1.1 μmol/L). The high affinity lysine site of plasminogen is involved in its binding to fibrin. Saturation of the high affinity binding site with tranexamic acid displaces plasminogen from the surface of fibrin. Although plasmin may be formed by conformational changes in plasminogen, binding to and dissolution of the fibrin matrix is inhibited.

1 INDICATIONS AND USAGE Tranexamic acid injection, USP is indicated in patients with hemophilia for short-term use (2 to 8 days) to reduce or prevent hemorrhage and reduce the need for replacement therapy during and following tooth extraction. Tranexamic acid injection is an antifibrinolytic indicated in patients with hemophilia for short-term use (2 to 8 days) to reduce or prevent hemorrhage and reduce the need for replacement therapy during and following tooth extraction. ( 1 )

2 DOSAGE AND ADMINISTRATION Before Extraction: Administer 10 mg/kg actual body weight of tranexamic acid injection intravenously with replacement therapy. ( 2.1 ) After Extraction: Administer 10 mg/kg actual body weight 3 to 4 times daily for 2 to 8 days. Infuse no more than 1 mL/minute to avoid hypotension. ( 2.1 ) Reduce the dosage for patients with renal impairment. ( 2.2 , 8.6 ) 2.1 Recommended Dosage The recommended dose of tranexamic acid injection is 10 mg/kg actual body weight intravenously administered as a single-dose, immediately before tooth extractions. Infuse no more than 1 mL/minute to avoid hypotension [see Warnings and Precautions ( 5.1 )]. Following tooth extraction, tranexamic acid injection may be administered for 2 to 8 days at a dose of 10 mg/kg actual body weight 3 to 4 times daily, intravenously. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. For intravenous infusion, tranexamic acid injection may be mixed with most solutions for infusion such as electrolyte solutions, carbohydrate solutions, amino acid solutions, and Dextran solutions. Heparin may be added to tranexamic acid injection. Tranexamic acid injection should NOT be mixed with blood. The drug is a synthetic amino acid and should NOT be mixed with solutions containing penicillin. Discard any unused portion. The diluted mixture may be stored for up to 4 hours at room temperature prior to patient administration. 2.2 Recommended Dosage for Patients With Varying Degrees of Renal Impairment * For patients with moderate to severe impaired renal function, the following dosages are recommended: Table 1: Recommended Dosage in Patients With Varying Degrees of Renal Impairment * Dose reduction is recommended for all doses, both before and after tooth extraction. Serum Creatinine (mg/dL) Tranexamic Acid Intravenous Dosage 1.36 to 2.83 (120 to 250 micromol/L) 10 mg/kg twice daily 2.83 to 5.66 (250 to 500 micromol/L) 10 mg/kg daily >5.66 (>500 micromol/L) 10 mg/kg every 48 hours or 5 mg/kg every 24 hours

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Thromboembolic Risk [see Warnings and Precautions ( 5.1 )] Seizures [see Warnings and Precautions ( 5.3 )] Hypersensitivity Reactions [see Warnings and Precautions ( 5.4 )] Visual Disturbances [see Warnings and Precautions ( 5.5 )] Dizziness [see Warnings and Precautions ( 5.6 )] Most common adverse reactions are nausea, vomiting, diarrhea, allergic dermatitis, giddiness, hypotension, and thromboembolic events. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Avenacy Inc. at 1-855-283-6229 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of tranexamic acid. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Gastrointestinal disturbances (nausea, vomiting, diarrhea) may occur and may resolve with dose-reduction. Allergic dermatitis and giddiness have been reported. Hypotension has been reported when intravenous injection is too rapid. Thromboembolic events (e.g., deep vein thrombosis, pulmonary embolism, cerebral thrombosis, acute renal cortical necrosis, and central retinal artery, vein obstruction and cases associated with concomitant use of combination hormonal contraceptives) have been rarely reported in patients receiving tranexamic acid for indications other than hemorrhage prevention in patients with hemophilia. Convulsion, cromatopsia, and visual impairment have also been reported. Anaphylaxis or anaphylactoid reactions have been reported that are suggestive of a causal relationship.

7 DRUG INTERACTIONS Prothrombotic Medical Products: Avoid concomitant use, can further increase the risk of thromboembolic adverse reactions associated with tranexamic acid. ( 5.1 , 7.1 , 8.3 ) 7.1 Prothrombotic Medical Products Avoid concomitant use of tranexamic acid injection with medical products that are prothrombotic because concomitant use can further increase the risk of thromboembolic adverse reactions associated with tranexamic acid [see Warnings and Precautions ( 5.1 ), Use in Specific Populations ( 8.3 )] .