MAJOR — Use With Caution
FDA-documented interaction. Monitor INR closely during erythromycin treatment.
Evidence level: STRONG
Erythromycin can increase warfarin blood-thinning effect through multiple mechanisms, raising your bleeding risk. Your doctor should monitor your blood clotting more closely.
Erythromycin inhibits CYP3A4, increasing warfarin levels. Also may affect vitamin K-producing intestinal flora. FDA warfarin label lists erythromycin as potentiating anticoagulant effect.
Get INR monitored within a few days of starting erythromycin. Report any unusual bleeding. Consider alternative antibiotics if available.
Monitor closely. Many antibiotics amplify anticoagulant effects by disrupting gut flora that produce vitamin K. Warfarin levels may spike during antibiotic courses. If on warfarin, request more frequent INR monitoring. Take each at their normal prescribed times.
Higher risk for: elderly patients, those with liver disease, history of GI bleeding, concurrent use of multiple blood thinners, recent surgery, vitamin K intake changes, alcohol use, or low body weight.
Easy bruising, nosebleeds, blood in urine or stool, prolonged bleeding
Discuss alternative antibiotics. Request INR monitoring schedule during and after treatment.
This medication combination requires careful medical oversight. Your doctor or anticoagulation clinic can adjust doses or select alternatives with fewer bleeding risks. Frequent INR monitoring is essential.
Erythromycin can increase warfarin blood-thinning effect through multiple mechanisms, raising your bleeding risk. Your doctor should monitor your blood clotting more closely.
Monitor closely. Many antibiotics amplify anticoagulant effects by disrupting gut flora that produce vitamin K. Warfarin levels may spike during antibiotic courses. If on warfarin, request more frequent INR monitoring. Take each at their normal prescribed times.
Easy bruising, nosebleeds, blood in urine or stool, prolonged bleeding
This medication combination requires careful medical oversight. Your doctor or anticoagulation clinic can adjust doses or select alternatives with fewer bleeding risks. Frequent INR monitoring is essential.
Discuss alternative antibiotics. Request INR monitoring schedule during and after treatment.
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