Emerging antithrombotic agents: what does the intensivist need to know?

As thrombus consists of both fibrin and platelets, antithrombotic strategies involve anticoagulants and antiplatelets, alone or in combination.

Traditionally, unfractionated heparin has been the most commonly used parenteral anticoagulant, but owing to its variable dose response and narrow therapeutic indices, it is being replaced by low molecular weight heparin, fondaparinux, and bivalrudin. New oral factor Xa inhibitors like apixaban and rivaroxaban are still on the horizon, awaiting definite evaluation in ACS, DVT and atrial fibrillation. On the contrary, a dramatic advance in the arena of oral anticoagulants has occurred with the introduction of dabigatran, an oral direct thrombin inhibitor. This agent showed better outcomes than oral vitamin K antagonists in patients with atrial fibrillation. The antiplatelet field has also expanded by the addition of two new agents, prasugrel and ticagrelor. These agents have been tested against clopidogrel, in patients with ACS, with superior efficacy outcomes for both agents and higher bleeding events with prasugrel.

Bleeding risk associated with antithrombotics is not only a function of their inherent biochemical properties but also a reflection of how healthcare professionals choose and dose these agents in individual patients.