(HealthDay News) — Concomitant use of a nonsteroidal anti-inflammatory drug (NSAID) or aspirin in patients with venous thromboembolism receiving anticoagulant therapy is tied to increased risk of bleeding, according to a study published online April 14 in JAMA Internal Medicine.
Bruce L. Davidson, MD, from the University of Washington in Seattle, and colleagues analyzed data from the EINSTEIN deep vein thrombosis and pulmonary embolism clinical trials comparing rivaroxaban with enoxaparin-vitamin K antagonist (VKA) treatment (2007–2009).
The researchers found that, during NSAID-anticoagulant concomitant treatment, clinically relevant bleeding occurred at an event rate of 37.5 per 100 patient-years vs. 16.6 per 100 patient-years during anticoagulant use only (hazard ratio [HR], 1.77), while major bleeding occurred at an event rate of 6.5 per 100 patient-years vs. 2.0 per 100 patient-years during nonuse (HR, 2.37). Clinically relevant bleeding occurred at an event rate of 36.6 per 100 patient-years with aspirin-anticoagulant concomitant treatment, compared to 16.9 per 100 patient-years during aspirin nonuse (HR, 1.70; 95% confidence interval [CI], 1.38–2.11), while major bleeding occurred at an event rate of 4.8 per 100 patient-years vs. 2.2 per 100 patient-years with nonuse (HR, 1.50; 95% CI, 0.86–2.62). Similar increases in risk for clinically relevant and major bleeding were seen with rivaroxaban and enoxaparin-VKA anticoagulation regimens.
“Among patients with venous thromboembolism receiving anticoagulant therapy, concomitant use of an NSAID or aspirin is associated with an increased risk of clinically relevant and major bleeding,” the authors write.
Several authors disclosed financial ties to pharmaceutical companies, including Bayer Healthcare and Janssen Pharmaceuticals, which sponsored the EINSTEIN clinical trials.