Moderate
Probable
描述
Valproic acid can displace warfarin from plasma protein binding sites and may inhibit platelet aggregation, increasing bleeding risk.
机制
Valproic acid displaces warfarin from albumin binding, transiently raising free warfarin concentrations; it also inhibits platelet aggregation independently through uncertain mechanisms.
临床意义
Total warfarin levels may appear unchanged while free fraction rises; bleeding risk is increased even without marked INR changes.
处理措施
Monitor INR and clinical signs of bleeding closely when combining; measure free warfarin levels if available. Adjust dose if INR changes.