EpistemisAndexanet Alfa
Common trade names: Ondexxya, Andexxa.
Mechanism
Pharmacological Group and Molecular Target
Inert biological molecular decoy. Modified human recombinant protein of Factor Xa.
Detailed Mechanism of Action
Direct Factor Xa inhibitors (apixaban, rivaroxaban, edoxaban) prevent the conversion of prothrombin to thrombin by binding to the catalytic site of functional Factor Xa. Andexanet alfa is a modified version of human Factor However, it retains an identical three-dimensional conformation at its active binding site, behaving as a high-affinity "decoy receptor" that rapidly captures and neutralizes free Factor Xa inhibitors in the plasma, releasing endogenous Factor Xa to resume the physiological coagulation process.
Indicators and dose
Specific Clinical Indications
- Reversal of anticoagulation in patients chronically treated with apixaban or rivaroxaban who experience acute life-threatening bleeding or active bleeding into critical organs (e.g., intracranial hemorrhage).
Dosage Scheme and Infusion Protocols
| Previous Anticoagulant | Last Take Dose | Time since Last Shot | Recommended Andexanet Alfa Regimen |
|---|---|---|---|
| Apixaban | 5 mg | Any or indeterminate | Low Dose Regimen: IV bolus of 400 mg at 30 mg/min + Continuous infusion of 480 mg at 4 mg/min for 120 minutes. |
| Apixaban | >5 mg or unknown | <8 hours or indeterminate | High Dose Regimen: IV bolus of 800 mg at 30 mg/min + Continuous infusion of 960 mg at 8 mg/min for 120 minutes. |
| Rivaroxaban | 10 mg | Any or indeterminate | Low Dose Regimen: IV bolus of 400 mg at 30 mg/min + Continuous infusion of 480 mg at 4 mg/min for 120 minutes. |
| Rivaroxaban | >10 mg or unknown | <8 hours or indeterminate | High Dose Regimen: IV bolus of 800 mg at 30 mg/min + Continuous infusion of 960 mg at 8 mg/min for 120 minutes. |
Security
Contraindications and Precautions
- Significant Thrombotic Risk (up to 10% of patients): By rapidly reversing factor Xa blockade, systemic thrombin generation can be uncontrollably reactivated. Events of myocardial infarction, ischemic stroke and pulmonary thromboembolism have been reported in the weeks following its use. Recommend prophylactic anticoagulation as soon as hemostasis has been safely established.
Epistemis is educational review material. It is not a medical device, does not diagnose or prescribe treatment, and does not replace formal medical training, current clinical guidelines, or professional clinical judgment.
- System
- Antidotes and Toxicology
- Cluster
- Reversal Modified Recombinant Protein