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Last sync to Obsidian:
20/09/2026, 22:47:09

Anticoagulant reversal

2 min read

Reversal of anticoagulation may be indicated in patient who require surgery, are actively bleeding, or those who are are overanticogulated for various reasons. It may also be used in treatment of anticoagulant overdose.

Warfarin

See warfarin reversal.

Dabigatran

Idarucizumab is a humanised monoclonal antibody fragment that binds dabigatran with an affinity 300 times greater than between thrombin and dabigatran. By complexing with dabigatran and its metabolites it neutralises the anticoagulant effect.

A pair of ampoules for a 5mg dose costs NZ$4250 (at 08/2026).

Rivaroxaban

In New Zealand at least, rivaroxaban cannot be reversed. Mostly because reversal with andexanet alfa costs tens of thousands of dollars.

The usually practice for patients requiring restoration of haemostasis is administration of prothrombin complex concentrate. It works sometimes, as demonstrated by the literature; one study put good haemostatic effectiveness at about 70%.1

Andexanet alfa is a recombinant form of human factor Xa designed to lack enzyme activity. It binds rivaroxaban and thus reduces inhibition of native FXa. It has also been observed to inhibit tissue factor pathway inhibitor which may explain is pro-thrombotic effects.

The ANDEXXA-I trial was AstraZeneca’s post marketing research and on presentation to the FDA the risks of andexanet alfa were felt to outweigh its benefits. Treatment with andexanet alfa produced excellent restoration of haemostasis but unfortunately increased risk of major thrombosis. The medication was voluntarily withdrawn and AstraZeneca ceased production for the US market in late 2025. Andexanet alfa remains available in the EU.

Apixaban

Also cannot be reversed. Similar to rivaroxaban, it is a direct FXa inhibitor. Apixaban is approved in New Zealand, but its use is not funded.

Further reading:

  • New Zealand Blood. Transfusion Medicine Handbook [Internet]. 3rd ed. NZBS; 2016. Link

Footnotes

  1. Majeed A, Ågren A, Holmström M, Bruzelius M, Chaireti R, Odeberg J, et al. Management of rivaroxaban- or apixaban-associated major bleeding with prothrombin complex concentrates: a cohort study. Blood. 2017 Oct 12;130(15):1706–12. doi:10.1182/blood-2017-05-782060 ↩