Moderate
Probable
Descripción
Doxycycline may enhance warfarin's anticoagulant effect, particularly in patients whose vitamin K intake is already limited.
Mecanismo
Doxycycline reduces intestinal flora that produce vitamin K2, potentially decreasing cofactor availability for synthesis of clotting factors II, VII, IX, and X.
Relevancia clínica
INR elevations are typically modest but can be clinically relevant in elderly patients or those with dietary vitamin K insufficiency.
Manejo clínico
Monitor INR after starting doxycycline; counsel patients on consistent dietary vitamin K intake during antibiotic therapy.