The drug is approved for emergency medical bleeds only, in particular, intracranial haemorrhages. However, it is important to note that there is no current surgical data supporting this particular use. A large study was conducted, which led to the drug’s approval both in the U.S. The drug effect on reversal is about three hours (Figure 1). Andexanet comes in vials that require mixing, and is given as a loading dose followed by an infusion of two hours. Once bound to andexanet, inhibitors are unable to bind/inhibit FXa (Ansell 2013). The two specific state of the art reversal agents (also called antidotes) that can be used to manage a major bleed include idarucizumab and andexanet. Managing bleeding is important, and developing a bleeding, and therapeutic plan is critical.

In case of elevated PT, this may represent high blood levels of DOACs or coagulopathy.

Normal PT and PTT do not rule out significant blood level of DOACs, especially anti-FXa agents.

Prothrombin time (PT)/ International normalised ratio (INR)/partial thromboplastin time (PTT) are relatively insensitive to the effects of anti-FXa agents and are reagent-dependent.

There are some important caveats to consider (Heidbuchel H et al. Measuring the effects of these new oral anticoagulants and nonvitamin K can be confusing for clinicians.

One is what's their renal function as it can have an impact on drug elimination, and the other is coagulation testing. When a patient comes in on a NOAC and needs emergency surgery or is actively bleeding, two important questions must be asked. In patients with acute bleeding, the concept of factor concentrates is to restore the levels of these agents.

Anticoagulants decrease circulating levels of factor II, VII, IX and X. These drugs are also reversible inhibitors versus warfarin or other vitamin K antagonist that are used in Europe.

Non-vitamin K oral anticoagulants (NOACs/DOACs) are direct reversible inhibitors of factor Xa.

Xa inhibitor reversal