Anticoagulation drug therapy: a review

Abstract

Historically, most patients who required parenteral anticoagulation received heparin, whereas those patients requiring oral anticoagulation received warfarin. Due to the narrow therapeutic index and need for frequent laboratory monitoring associated with warfarin, there has been a desire to develop newer, more effective anticoagulants. Consequently, in recent years many novel anticoagulants have been developed. The emergency physician may institute anticoagulation therapy in the short term (e.g. heparin) for a patient being admitted, or may start a novel anticoagulation for a patient being discharged. Similarly, a patient on a novel anticoagulant may present to the emergency department due to a hemorrhagic complication. Consequently, the emergency physician should be familiar with the newer and older anticoagulants. This review emphasizes the indication, mechanism of action, adverse effects, and potential reversal strategies for various anticoagulants that the emergency physician will likely encounter.

Figure 1

The coagulation cascade.

Figure 2

Site of action of drugs. Modified, with permission, Gresham C, Levine M, Ruha AM.

Figure 3

Comparison table for anticoagulants.,,, PT, pro-thrombin time; INR, international normalized ratio; HIT, heparin-induced thrombocytopenia; PO, oral administration; IV, intravenous; FFP, fresh frozen plasma; aPTT, activated partial thromboplastin time; UFH, unfractionated heparin; PCC, prothrombin complex concentrates