Major
Established
Mô tả
Naproxen combined with warfarin increases the risk of GI and other hemorrhagic complications through additive effects on hemostasis and direct gastric mucosal damage.
Cơ chế
Naproxen inhibits COX-1–mediated platelet aggregation and damages gastric mucosa, compounding warfarin's anticoagulant effect and creating a site for bleeding.
Ý nghĩa lâm sàng
Significant increase in upper GI bleeding risk; the interaction is pharmacodynamic and does not require INR to be supratherapeutic for bleeding to occur.
Xử trí
Avoid if possible; use acetaminophen instead. If required, add a PPI, use the lowest effective naproxen dose for the shortest duration, and monitor for signs of bleeding.