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