Major
Clopidogrel × Warfarin
Antiplatelet agents – P2Y12 receptor inhibitors×Vitamin K antagonist anticoagulants
Mechanism
Warfarin blocks vitamin K-dependent clotting factor synthesis; clopidogrel inhibits platelet aggregation via the P2Y12 receptor. The two antithrombotic mechanisms add up.
Symptoms
Gum bleeding, epistaxis, bruising without trauma, blood in urine or stool, menorrhagia. Severe cases include gastrointestinal or intracranial haemorrhage. Risk rises in patients over 65 and with prior peptic ulcer disease.
Management
Combine only for clear indications (e.g., atrial fibrillation plus coronary stent). Limit dual therapy to 1–6 months depending on risk. Keep INR at the lower end of the target range (2.0–2.5) and provide PPI cover with pantoprazole.
Sources
- ESC: 2023 ESC Guidelines for the management of acute coronary syndromes (2023)– Eur Heart J 2023;44(38):3720–3826
- ESC: 2024 ESC Guidelines for the management of atrial fibrillation developed in collaboration with the EACTS (2024)– Eur Heart J 2024;45(36):3314–3414
- AUGUSTUS Investigators: Antithrombotic Therapy after Acute Coronary Syndrome or PCI in Atrial Fibrillation (2019)– N Engl J Med 2019;380(16):1509–1524