II. Background

  1. Released 2018 in U.S.

III. Mechanism

  1. Andexxa is a Inactivated Recombinant Factor Xa decoy Protein that binds Factor Xa Inhibitors
  2. Factor Xa Inhibitors are not irreversibly bound, and rebound bleeding may occur after infusion
  3. Antidote studied for Eliquis (Apixaban) or Xarelto (Rivaroxaban)
    1. Thought to be effective for other Factor Xa Inhibitors (Edoxaban, Betrixaban)

IV. Dosing

  1. Low Dose: 400 mg IV bolus (at 30 mg/min), followed by infusion at 4 mg/min for 2 hours
    1. Indicated if last DOAC dose >8 hours ago, or if high dose criteria not met
  2. High Dose: 800 mg IV bolus (at 30 mg/min), followed by infusion at 8 mg/min for 2 hours
    1. Indicated for Apixaban >5 mg/dose, Rivaroxaban 10 mg/dose or unknown dose

V. Efficacy

  1. Limits progression of bleeding within 12 hours of dose (onset as early as 1 hour)
  2. Excellent or good Hemostasis in 82% of patients in ANNEXa-4 study
  3. Ineffective in the 25% of patients who have low anti-Factor Xa Inhibitor

VI. Adverse Effects

  1. Expensive: $25,000 to 50,000 per patient
  2. Infusion site reaction (10%)
  3. Risk of Hypercoagulability complications (CVA, VTE, MI)
    1. FDA black box warning
    2. Thrombosis risk at 30 days: 10% (contrast with 3 to 8% with PCC4)
    3. Deep Vein Thrombosis (6%)
    4. Ischemic Cerebrovascular Accident (5%)
  4. Infections
    1. Urinary Tract Infection (5%)
    2. Pneumonia (5%)
  5. Rebound bleeding (return of Xa activity)
    1. Repeat bleeding may occur after initially controlled following Andexanet Alfa
    2. Avoid repeating Andexanet Alfa
    3. Consider Prothrombin Complex Concentrate (PCC4)

VIII. References

  1. (2018) Presc Lett 25(7): 37-8
  2. Cook and Mishler (2018) Crit Dec Emerg Med 32(8): 32
  3. Ebersole, Toomey and Baugh (2021) Crit Dec Emerg Med 35(5): 3-9
  4. Connolly (2019) N Engl J Med 380(14):1326-35 +PMID:30730782 [PubMed]

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