FDA has recently approved rivaroxaban (Xarelto, Janssen Pharmaceuticals) for treatment of acute deep vein thrombosis (DVT) and pulmonary embolism and for prevention of recurrences. These indications are in addition to the drug’s previous approvals for prevention of thromboembolism and stroke in patients with nonvalvular atrial fibrillation and for DVT prevention in patients undergoing joint surgery.
The approval was based mainly on results from three trials with a total of 9,478 patients randomized to rivaroxaban, placebo, or enoxaparin (Lovenox, Sanofi-Aventis) combined with a vitamin K antagonist such as warfarin (Coumadin, Bristol-Myers Squibb). Those trials showed that rivaroxaban was as effective as the enoxaparin and vitamin K antagonist combination for treating DVT and pulmonary embolism. A placebo-controlled trial showed that 1.3% of patients taking rivaroxaban had recurrent thromboembolic events compared with 7.1% of those assigned to placebo.
The studies also indicated that rivaroxaban has a lower risk of bleeding events. For example, in the EINSTEIN-PE trial, reported earlier this year in the New England Journal of Medicine and at the American College of Cardiology’s annual meeting, 1.1% of patients on rivaroxaban experienced major bleeding versus 2.2% with enoxaparin (P=.003).
A major advantage of rivaroxaban, an oral Factor Xa inhibitor, is that it doesn’t require monitoring of coagulation activity. Its major adverse event is increased risk of bleeding, as is the case with all other anticoagulants.
Source: FDA expands use of Xarelto to treat, reduce recurrence of blood clots. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm326654.htm. Accessed November 19, 2012.
A study presented at the European Society of Cardiology 2012 Congress indicates that patients treated with oral anticoagulants and who are receiving stents do not need the addition of aspirin to their drug regimen.
The trial showed a large reduction in overall bleeding in patients receiving dual therapy with oral anticoagulants and clopidogrel compared with those receiving triple therapy including aspirin. Efficacy was not compromised and there actually appeared to be lower rates of ischemic events and a significant reduction in all-cause mortality.
The trial included 573 patients already treated with oral anticoagulants for atrial fibrillation or mechanical valves and undergoing coronary stenting were prospectively randomized to two groups: one given additional clopidogrel only (double therapy group), or a second given additional clopidogrel and aspirin (triple therapy group). Each was followed for one year.
The data presented showed cumulative incidence of bleeding in the triple therapy group to be 44.9%, whereas the double therapy group had an incidence of bleeding of 19.5%. The cumulative mortality was 6.4% for the triple therapy group versus 2.6% for the anticoagulant/clopidogrel group.
Source: http://www.theheart.org/article/1439915.do. Accessed November 19, 2012
Low-dose aspirin may benefit patients who have completed an initial course of anticoagulation therapy for venous thromboembolism, a recent study indicates.
Although the researchers found that aspirin did not significantly reduce the recurrence of venous thromboembolism compared with placebo, they did find that aspirin provided a net clinical benefit.
The investigators randomly assigned 822 patients who had completed initial anticoagulant therapy after a first episode of unprovoked VTE to receive 100 mg of aspirin daily or placebo for up to 4 years. The primary outcome was a recurrence of venous thromboembolism.
During a median follow-up period of 37.2 months, venous thromboembolism recurred in 73 of 411 patients assigned to placebo and in 57 of 411 assigned to aspirin (P=.09). Aspirin reduced the rate of the secondary outcomes (myocardial infarction, stroke, or cardiovascular death) by 34% (P=.01). The rate of venous thromboembolism, myocardial infarction, stroke, major bleeding, or death from any cause was reduced by 33% (P=.01). There was no significant difference in the rates of bleeding.
Source: Brighton TA, Eikelboom JW, Mann K, et al. Low-dose aspirin for preventing recurrent venous thromboembolism.
N Engl J Med. 2012; 367:1979–1987. (http://www.nejm.org/doi/full/10.1056/NEJMoa1210384#t=article)
Anna D. Garrettis a clinical pharmacist and president of Dr. Anna Garrett, a health and wellness coaching company, Asheville, N.C.