HelixTalk Episode #3 - Novel Oral Anticoagulants (NOACs)

Date posted: May 6, 2014, 6:00 am

In this episode, we discuss the new drug class of Novel Oral Anticoagulants (NOACs), which include dabigatran (Pradaxa), rivaroxaban (Xarelto), and apixaban (Eliquis).

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Key Concepts

1. Dabigatran (Pradaxa) is a direct factor II (thrombin) inhibitor.  Rivaroxaban (Xarelto) and apixaban (Eliquis) are direct factor X inhibitors.  All three of these novel oral anticoagulants (NOACs) work by inhibiting a component of the clotting cascade.
2. Most NOACs are approved for non-valvular atrial fibrillation, treatment of DVT/PE, extended treatment of DVT/PE, and DVT prophylaxis after hip/knee replacement surgery.
3. Compared to warfarin, NOACs do not require INR monitoring, are renally eliminated, have an almost immediate onset of anticoagulant effect, and have fewer drug interactions.  Reversal for bleeding is not as straightforward as warfarin, although this is an area of interest for drug companies.
4. Compared to warfarin in atrial fibrillation, NOACs reduce the risk of stroke or systemic embolism by about 20% (NNT 142) and the risk of intracranial hemorrhage by about 50% (NNT 142).  Apixaban may have a more favorable bleeding profile than the other NOACs and warfarin.
5. In the setting of venous thromboembolism treatment and prevention (DVT/PE), the NOACs are generally equally effective to enoxaparin and/or warfarin.
6. Dabigatran (Pradaxa) does have special storage requirements due to a desiccant in the bottle.  It is available in blister packs by the manufacturer if unit dosing is required.
7. Rivaroxaban (Xarelto) should be taken with food to increase oral bioavailability.
8. Given that these NOACs are newer agents, the indications, warnings, and other relevant clinical pearls may change over time as more data becomes available.