Quick primer on idarucizumab and NOAC-associated bleeding

What is idarucizumab (Praxbind), and why was it developed? When is idarucizumab prescribed, and when is it not?

What is idarucizumab, and why was it developed?

Idarucizumab is a specific reversal agent for dabigatran.1 It is the first specific ‘antidote’ for a non-vitamin K antagonist oral anticoagulant (NOAC) to be approved in Australia.

Idarucizumab was developed because, like warfarin and the other NOACs,2-5 dabigatran can increase the risk of bleeding and can cause significant and sometimes fatal bleeding.6

People who are taking dabigatran and have surgery or invasive procedures are also at increased risk of bleeding.6

Protocols to reverse warfarin’s anticoagulant effects are well established. Vitamin K can reverse warfarin’s anticoagulant effects, and prothrombin complex concentrates (a type of pro-haemostatic agent) can correct low levels of factors II, VII, IX and X induced by warfarin.7

However, vitamin K is not expected to reverse NOAC-associated anticoagulation, and there are currently limited clinical data to support the routine use of pro-haemostatic agents for NOAC reversal.4-6,8,9

Pro-haemostatic agents may also increase the risk of thromboembolic complications when used for NOAC reversal.5,6,8,9

Although clinical data to support the use of idarucizumab are still limited, efficacy and safety in patients requiring urgent dabigatran reversal have been investigated in the open-label, phase III RE-VERSal Effects of idarucizumab on Active Dabigatran (RE-VERSE AD) study.10,11

Other NOAC reversal agents are under development but are not yet approved for use and require further clinical evaluation.8,12

 

When should idarucizumab be prescribed?

Idarucizumab is only used when the rapid reversal of the anticoagulant effect of dabigatran is required for emergency situations.1

When there is life-threatening bleeding

There are several steps involved for managing a patient who is experiencing severe bleeding. The first steps include:8,9

  • determining which particular NOAC the patient is taking and when they last took it
  • initiating standard rescuitation procedures
  • taking blood from the patient for anticoagulant monitoring

The next steps will depend on the severity of the bleed. Local haemostatic measures are used for mild bleeding.8

Idarucizumab can also be considered when there is clinically significant or life-threatening bleeding. Activated charcoal, hydration, transfusion support and/or pro-haemostatic agents can also be considered.8

Bleeding should be managed on a case-by-case basis, and in consultation with a haematologist.8

When an urgent surgery or procedure is needed

Idarucizumab can be considered when a patient taking dabigatran needs an urgent surgery or procedure, and there is insufficient time to allow for dabigatran clearance.6

For planned surgical or invasive procedures in people taking any of the NOACs, bleeding risk is managed by treatment interruption rather than reversal.6,8,9

In such cases, timing of NOAC cessation will depend on level of renal function, estimated NOAC half-life and level of bleeding risk associated with a particular surgery.8,9

The decision to withdraw or reverse a NOAC should also be weighed against the risk of exposing a person to thrombotic events due to their underlying condition.1,4-6

There are no contraindications to idarucizumab use, although there are precautions. Refer to the idarucizumab Product Information for complete prescribing information.1

 

References

  1. Boehringer Ingelheim Pty Limited. Idarucizumab (Praxbind) Product Information 2020 North Ryde, NSW: Boehringer Ingelheim Pty Ltd (accessed 17 February 2021).
  2. Mylan Health Pty Ltd. Warfarin (Coumadin) Product Information 2020. Millers Point, NSW: Mylan Health Pty Ltd (accessed 17 February 2021).
  3. Mylan Health Pty Ltd. Warfarin (Marevan) Product Information 2020. Millers Point, NSW: Mylan Health Pty Ltd(accessed 17 February 2021).
  4. Bayer Australia Ltd. Rivaroxaban (Xarelto) Product Information 2020 Pymble, NSW: Bayer Australia Ltd (accessed 17 February 2021).
  5. Bristol-Myers Squibb Australia Pty Ltd. Apixaban (Eliquis) Product Information 2020 Sydney, NSW: Bristol-Myers Squibb Australia Pty Ltd (accessed 17 February 2021).
  6. Boehringer Ingelheim Pty Limited. Dabigatran etexilate (Pradaxa) Product Information 2020 North Ryde, NSW: Boehringer Ingelheim Pty Ltd (accessed 17 February 2021)).
  7. Tran HA, Chunilal SD, Harper PL, et al. An update of consensus guidelines for warfarin reversal. Med J Aust 2013;198:198-9.
  8. Clinical Excellence Commission. Non-vitamin K antagonist oral anticoagulant (NOAC) guidelines. Sydney, Australia, 2016 (accessed 28 November 2016).
  9. Tran H, Joseph J, Young L, et al. New oral anticoagulants: a practical guide on prescription, laboratory testing and peri-procedural/bleeding management. Australasian Society of Thrombosis and Haemostasis. Intern Med J 2014;44:525-36.
  10. Pollack CV, Jr. Evidence supporting idarucizumab for the reversal of dabigatran. Am J Med 2016;129:S73-S9.
  11. Pollack CV Jr, Reilly PA, van Ryn J, et al. Idarucizumab for Dabigatran Reversal - Full Cohort Analysis. N Engl J Med. 2017;377(5):431-441. doi:10.1056/NEJMoa1707278
  12. Kirchhof P, Benussi S, Kotecha D, et al. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS: The Task Force for the management of atrial fibrillation of the European Society of Cardiology (ESC). Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Endorsed by the European Stroke Organisation (ESO). Eur Heart J 2016;37:2893-2962.