Moderate
Amiodarone × Clopidogrel
Class III antiarrhythmics (Vaughan Williams)×Antiplatelet agents – P2Y12 receptor inhibitors
Mechanism
Amiodarone weakly inhibits CYP2C19, the key enzyme that converts clopidogrel to its active metabolite. Effect is clinically minimal; no proven reduction in antiplatelet activity.
Symptoms
The combination usually causes no specific symptoms. Baseline clopidogrel bleeding risk and amiodarone bradycardia risk remain.
Management
No dose adjustment needed. After acute coronary syndrome, if antiplatelet activity is in doubt, consider switching to ticagrelor or prasugrel (CYP2C19-independent).