The new oral anticoagulants: Reasonable alternatives to warfarin

Abstract

Dabigatran (a direct thrombin inhibitor) and rivaroxaban, apixaban, and edoxaban (direct activated factor X inhibitors) are increasingly being used in clinical practice. Compared with vitamin K antagonists, they are more convenient, do not require laboratory monitoring, have limited drug and food interactions, and have fixed dosages suitable for most patients. But the shortcomings of these agents can jeopardize their efficacy and increase the risk of bleeding. Their future role in preventing and treating thromboembolic disease will depend on building clinical experience, but current evidence indicates that they are reasonable alternatives to vitamin K antagonists.

Hypereosinophilic syndrome presenting with multiple organ infiltration and deep venous thrombosis

“…[4,25] Though the standard care of DVT is LMWH followed by a vitamin K antagonist, in our case we initially chose a Factor Xa inhibitor, rivaroxaban, in the setting of thrombocytopenia and suspected DIC, since some literatures indicate that a Factor Xa inhibitor may cause fewer major bleeding events than warfarin or LMWH. [26–28] After the use of steroid and rivaroxaban, the patient's EO followed with platelet count recovered and the swollen extremity progressively improved, but the fibrinogen level remained low. We subsequently converted rivaroxaban to enoxaparin, and the fibrinogen levels remained stable after the cryoprecipitate transfusion.…”

Efficacy and Safety of Direct-Acting Oral Anticoagulants Use in Acute Portal Vein Thrombosis Unrelated to Cirrhosis

“…This because it has been postulated that lower portal flow velocities, which may raise the risk of PVT development, may lead to a lower wash out of active thrombin generated in portal circulation and thus contribute to a “local” higher prothrombotic environment [11]. Other major concern about DOACs use is also its safety, since they all are metabolized in the liver [4]. …”

“…In contrast, if anticoagulation is not started, recanalization is exceptional [1, 3]. The use of DOACs is being generalized [4], but they are not routinely used in PVT and are not yet mentioned in the latest guidelines as an alternative treatment [1]. Recent data, however, indicate that this new class of anticoagulants is increasingly used also in patients with splanchnic vein thrombosis [5, 6].…”

Carbon‐13 and carbon‐14 labeled dabigatran etexilate and tritium labeled dabigatran

“…Dabigatran etexilate was the first FDA‐approved alternative to warfarin and is now used to prevent strokes in patients with atrial fibrillation (AFib) and the formation of blood clots in the veins (deep venous thrombosis) in adults who have had an operation to replace a hip or a knee . Dabigatran etexilate also known as pradaxa is the only novel oral anticoagulant (NOAC) with a specific reversal agent for use in rare emergency situations . Following oral administration, dabigatran etexilate is rapidly converted to its active form by human carboxylesterase enzymes as shown in Scheme .…”

“…24 Dabigatran etexilate also known as pradaxa is the only novel oral anticoagulant (NOAC) with a specific reversal agent for use in rare emergency situations. 25 Following oral administration, dabigatran etexilate is rapidly converted to its active form by human carboxylesterase enzymes as shown in Scheme 1. 26 In this manuscript, we report the synthesis of this drug labeled with carbon-13, carbon-14, and tritium.…”