## Primary Drug Warfarin ## Interacting Drug Amiodarone ## Type of Interaction Pharmacokinetic ## Mechanism Amiodarone inhibits the metabolism of warfarin, primarily through the inhibition of CYP2C9 and CYP3A4 enzymes, leading to increased levels of warfarin in the blood. ## Clinical Significance This interaction can significantly increase the anticoagulant effects of warfarin, potentially leading to an elevated risk of bleeding. ## Management / Monitoring Close monitoring of INR (International Normalized Ratio) levels is essential when warfarin is co-administered with amiodarone. Dosage adjustments of warfarin may be necessary to maintain therapeutic anticoagulation. ## Pharmacy Technician Notes - Patients should be advised to report any signs of bleeding or bruising promptly to their healthcare provider. - Counseling should emphasize the importance of regular INR monitoring to ensure the safe and effective use of warfarin. - Encourage patients to inform all healthcare providers about the use of both warfarin and amiodarone to avoid potential drug interactions.