Clopidogrel

PLAVIX

Open Clopidogrel in the interactive console ↗

What it isIrreversible P2Y12 antiplatelet prodrug; secondary prevention after acute coronary syndrome or ischemic stroke.

Why this oneIt is the generic oral backbone of dual antiplatelet therapy, but response depends on CYP2C19 activation unlike ticagrelor.

What limits itPoor CYP2C19 metabolism and omeprazole can blunt efficacy; bleeding and perioperative interruption require planning.

FDA-approved for

acute coronary syndrome/stroke prevention (1997)

FDA label

Read the full label on DailyMed ↗

BOXED WARNING Diminished antiplatelet effect in CYP2C19 poor metabolizers; consider an alternative P2Y12 inhibitor.

FDA dosing	Population	Start	Target	Max
Acute coronary syndrome	Adult	300 mg loading dose once, then 75 mg QD	75 mg QD
Recent MI, recent stroke, or established peripheral arterial disease	Adult	75 mg QD (no loading dose)	75 mg QD

Renal Limited experience in moderate-to-severe renal impairment

Hepatic No adjustment needed

Instructions

Initiating without a loading dose (ACS) delays antiplatelet effect by several days
Interrupt therapy 5 days before elective surgery with major bleeding risk; resume as soon as hemostasis achieved

Contraindications

Active pathological bleeding (e.g., peptic ulcer, intracranial hemorrhage)

Cautions

Increased risk of bleeding
Premature discontinuation increases risk of cardiovascular events
Thrombotic thrombocytopenic purpura (may be fatal, even after <2 weeks)
Cross-reactivity among thienopyridines
Reduced effectiveness in CYP2C19 poor metabolizers

Adverse reactions

Bleeding (including life-threatening and fatal)
Epistaxis
Hematuria/hematoma/bruise
Pruritus
Thrombotic thrombocytopenic purpura

Pregnancy No drug-associated risk identified; discontinue 5-7 days before labor/delivery or neuraxial blockade (maternal bleeding/spinal hematoma risk)

Lactation No human data; present in rat milk

⚠ BOXED WARNING