warfarin + acetylsalicylic acid

Warfarin + acetylsalicylic acid refers to the two primary antithrombotic regimens evaluated by the Hamilton Health Sciences Corporation for thromboprophylaxis in pediatric patients following Fontan surgery. In the landmark international multicenter randomized clinical trial (NCT00182104), these agents were compared as distinct treatment strategies: one arm received warfarin (with an initial heparin lead-in) to maintain an international normalized ratio (INR) of 2.0–3.0, while the other received acetylsalicylic acid (aspirin) at a dose of 5 mg/kg/day. Warfarin acts as a vitamin K antagonist by inhibiting the enzyme vitamin K epoxide reductase complex subunit 1 (VKORC1), thereby preventing the recycling of vitamin K and the subsequent carboxylation of clotting factors II, VII, IX, and X. Acetylsalicylic acid functions as an antiplatelet agent by irreversibly inhibiting cyclooxygenase-1 (COX-1), which blocks the synthesis of thromboxane A2. The trial concluded that there was no significant difference in thrombosis rates between the two regimens over a two-year follow-up period, with both showing suboptimal efficacy in this high-risk population.

Other names

warfarin and aspirinASA and warfarinaspirin and warfarin