New Oral Anticoagulants (NOACs)

New oral anticoagulants (NOACs) have revolutionized anticoagulant therapy in recent years. Although the NOACs have limitations in terms of patients who can benefit from them, they have been shown to be effective for treating various conditions.

NOACs have altered the previously accepted therapeutic choices for anticoagulation. NOACs are intended to replace warfarin treatment. The benefits of these drugs include the fact that laboratory testing to monitor therapy is not required. Additional benefits include reduced food and drug interactions and rapid onset of action. However, these drugs are not without their laboratory testing challenges and clinical limitation (Table 1).

The NOACs are a novel class of oral anticoagulants that directly target activated coagulation factors, unlike vitamin K antagonists (VKA). These drugs act directly on specific activated factors. The NOACS have been found to be effective and safe compared with VKA for treating or preventing blood clots in coagulation disorders.

In 2009, the first oral thrombin (factor IIa) inhibitor was approved by the United States Food and Drug Administration (FDA). Two years later, the first of the oral direct factor Xa inhibitors was approved by the FDA.

The terms new oral anticoagulants (NOACs), direct oral anticoagulants, or target-specific oral anticoagulants refer to those oral anticoagulants which specifically inhibit factors IIa (thrombin) or factor Xa. The two broad classes of NOACs are: