Section 13 · Monograph
Clopidogrel
Reviewed Nov 2026FDA label
PlavixAntiplatelet (P2Y12)
- Forms
- Tab: 75, 300mg
- Dose
- 75mg daily | Minor stroke/high-risk TIA: 300-600mg load, then 75mg daily + aspirin for 21 days
- MOA
- Irreversible P2Y12 receptor blockade
Black Box Warning
- Diminished antiplatelet effect in patients with two loss-of-function CYP2C19 alleles (poor metabolizers); consider an alternative platelet P2Y12 inhibitor if known
Indications
- Acute coronary syndromeFDA-labeled
- Recent MI, recent stroke, or established peripheral arterial diseaseFDA-labeled
- Minor ischemic stroke or high-risk TIA with aspirin (guideline-supported, 21 days)FDA-labeled
Mechanism of Action
- Prodrug activated by CYP2C19; irreversibly blocks the platelet P2Y12 ADP receptor for the platelet lifespan
Full Dosing
Adult / usual
- Usual dose 75mg once daily
- Minor stroke/high-risk TIA (dual antiplatelet therapy): 300-600mg load then 75mg daily plus aspirin for 21 days, then single antiplatelet
- ACS: 300-600mg loading dose then 75mg daily
Contraindications
- Active pathological bleeding (peptic ulcer, intracranial hemorrhage)
- Known hypersensitivity
Drug Interactions
- Omeprazole and esomeprazole (CYP2C19 inhibition) reduce activation — avoid combination
- Anticoagulants, aspirin, NSAIDs increase bleeding risk
- May increase repaglinide levels (CYP2C8)
Adverse Effects
- Bleeding
- Thrombotic thrombocytopenic purpura (rare)
- Rash, diarrhea, dyspepsia
Monitoring Parameters
- Bleeding signs
- CBC
- Consider CYP2C19 genotyping where it would change therapy
Pregnancy & Lactation
- Limited data; use only if clearly needed
- Unknown whether present in human milk