For the treatment of acute venous thromboembolism (VTE), a fixed dose of the new anticoagulant dabigatran (Pradaxa; Boehringer Ingelheim) is as effective as warfarin, has a safety profile that is similar to that of warfarin and does not require laboratory monitoring, based on the findings of the RE-COVER trial published online Dec. 6 in the New England Journal of Medicine.
The direct oral thrombin inhibitor dabigatran has a predictable anticoagulant effect and may be an alternative therapy to warfarin for patients who have acute VTE, according to Sam Schulman, MD, from the HHS-General Hospital in Hamilton, Onatrio, and the RE-COVER study group.
In a randomized, double-blind, noninferiority trial involving patients with acute VTE, who were initially given parenteral anticoagulation therapy for a median of nine days, the researchers compared oral dabigatran, administered at a dose of 150 mg twice daily, with warfarin that was dose-adjusted to achieve an international normalized ratio of 2.0 to 3.0.
The primary outcome was the six-month incidence of recurrent symptomatic, objectively confirmed VTE and related deaths. Safety endpoints included bleeding events, acute coronary syndromes, other adverse events, as well as the results of liver-function tests.
The investigators found that 2.4 percent of patients randomly assigned to receive dabigatran, compared with 2.1 percent randomly assigned to warfarin, had recurrent VTE—the difference in risk was 0.4 percentage points. Also, the hazard ratio with dabigatran was 1.10.
Major bleeding episodes occurred in 1.6 percent of patients assigned to dabigatran and in 1.9 percent of patients assigned to warfarin, and episodes of any bleeding were observed in 16.1 percent of patients assigned to dabigatran and 21.9 percent of patients assigned to warfarin, according to the authors.
The authors noted that these findings “are consistent with data on bleeding from the RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) trial.”
They wrote that the numbers of deaths, acute coronary syndromes and abnormal liver-function tests were similar in the two groups.
However, adverse events leading to discontinuation of the study drug occurred in 9 percent of patients assigned to dabigatran and in 6.8 percent of patients assigned to warfarin.
Schulman and colleagues concluded that their trial provides data to support dabigatran as a fixed-dose oral treatment for acute deep-vein thrombosis and pulmonary embolism.
“For patients and health care providers, dabigatran is a far more convenient drug than warfarin because it has no known interactions with foods and minimal interactions with other drugs and therefore does not require routine blood-coagulation testing,” the authors wrote.
The study was supported by Boehringer Ingelheim.