Dabigatran: an oral direct thrombin inhibitor for use in atrial fibrillation

Atrial fibrillation (AF) is well known as one of the leading causes of stroke and systemic embolism. Anticoagulation therapy is recommended in all patients at moderate-to-high risk of stroke. The vitamin K antagonist warfarin has traditionally been used in these patients but presents challenges in dosing and monitoring in these patients. The oral direct thrombin inhibitor dabigatran etexilate (Pradaxa®; Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA) was recently approved for use in the US for preventing stroke and systemic embolism in patients with nonvalvular AF. Clinical trials have shown it to reduce the risk of stroke and systemic embolism when compared with warfarin (goal international normalized ratio [INR] 2–3) with a similar risk for severe bleeding. It can be given twice daily, with the dose adjusted for renal function. It does not have any dietary restrictions, has few drug interactions (except involving permeability [P]-glycoprotein [P-gp] agents), and does not require routine laboratory monitoring. Patients may experience significant dyspepsia with its use. Compared with warfarin there is increased risk for gastrointestinal bleeding and perhaps myocardial infarction. Currently, no reversal agent exists for use in situations of overdose or severe bleeding although some strategies have been suggested. Despite its high acquisition cost compared with warfarin, analysis using theoretical models has shown it to be cost-effective. Dabigatran offers a unique alternative to warfarin in patients with nonvalvular AF and can be beneficial in patients requiring anticoagulation therapy.