Moderate
Probable
الوصف
Hydroxychloroquine may potentiate the anticoagulant effect of warfarin, raising INR and the risk of bleeding complications.
الآلية
The mechanism is not fully established; proposed mechanisms include inhibition of CYP2C9 and CYP3A4, as well as independent antiplatelet properties of hydroxychloroquine.
الأهمية السريرية
Several case reports and pharmacovigilance analyses document significant INR elevation and bleeding events when hydroxychloroquine is added to warfarin.
التدبير
Monitor INR frequently when starting hydroxychloroquine in warfarin-treated patients; adjust warfarin dose as needed.