Moderate
Probable
설명
Azithromycin can potentiate the anticoagulant effect of warfarin, leading to elevated INR and increased bleeding risk during and shortly after the antibiotic course.
기전
Proposed mechanisms include inhibition of CYP1A2 and possible disruption of gut flora that synthesize vitamin K2 (menaquinones), reducing vitamin K availability for clotting factor synthesis.
임상적 중요성
Case reports and pharmacovigilance data document supratherapeutic INR elevations; major bleeding has been reported.
관리 방법
Monitor INR within 3–5 days of starting and after completing azithromycin; adjust warfarin dose if INR rises above target range.