Dabigatran

Dabigatran, marketed as dabigatran etexilate (Pradaxa), is an oral direct thrombin inhibitor used as an anticoagulant. It is a prodrug that is converted to the active dabigatran in the body and belongs to the class of direct oral anticoagulants (DOACs).

Dabigatran is indicated for reducing the risk of stroke and systemic embolism in adults with nonvalvular atrial fibrillation, for the treatment of deep vein thrombosis and pulmonary embolism, and for prophylaxis of venous thromboembolism after certain orthopedic surgeries in regions where approved. It is not approved for use in patients with mechanical heart valves. Dosing and approved indications vary by region and are guided by labeling; renal function and age influence dosing and suitability.

Mechanism of action: dabigatran directly inhibits thrombin (factor IIa), preventing conversion of fibrinogen to fibrin and thereby reducing thrombus formation. This also diminishes thrombin-triggered platelet activation.

Administration and dosing considerations: taken orally, typically twice daily for most indications. For venous thromboembolism treatment, dabigatran is usually started after an initial period of parenteral anticoagulation, with doses adjusted for renal function and age. It is primarily excreted by the kidneys, so severe renal impairment is a contraindication and mild-to-moderate impairment requires dose adjustments. It should be used with caution in elderly patients.

Adverse effects and safety: the major risk is bleeding. Common nonhemorrhagic effects include dyspepsia and other gastrointestinal symptoms. There is a risk of serious bleeding with procedures or in patients with concomitant risk factors. Special caution is advised with neuraxial anesthesia due to potential hematoma. Dabigatran is not recommended in certain populations, including those with mechanical heart valves.

Monitoring and reversal: routine coagulation monitoring is not required, but certain tests (eg, thrombin time, dilute thrombin time, or specialized assays) can reflect dabigatran activity; prothrombin time is not reliably sensitive. In cases of major bleeding or emergency reversal, idarucizumab (a reversal agent) is available.