Clopidogrel Bisulfate is an oral thienopyridine antiplatelet drug that inhibits platelet aggregation by irreversibly inhibiting the P2Y12 ADP receptor on the platelet surface.

I. Mechanism of Action and Clinical Role

Drug class: Clopidogrel Bisulfate is a thienopyridine P2Y12 receptor inhibitor. It is a prodrug that is metabolized by hepatic CYP2C19 into its active component.

Mechanism of action: The active metabolite irreversibly inhibits the P2Y12 receptor on the platelet surface, blocking ADP-mediated platelet activation and aggregation, thereby exerting an antithrombotic effect.

Clinical uses: It is mainly used for acute coronary syndrome (ACS), prevention of stent thrombosis after percutaneous coronary intervention (PCI), and secondary prevention of ischemic stroke and peripheral arterial disease.

II. Common Treatment Regimens

Loading dose: Patients with ACS or undergoing PCI often require a loading dose of 300–600 mg to rapidly achieve an antiplatelet effect; the specific dose is determined by the physician.

Maintenance dose: 75 mg once daily for long-term oral administration.

Dual antiplatelet therapy (DAPT): After PCI, it is usually combined with aspirin; the course of treatment depends on the stent type and bleeding risk, generally 6–12 months, and must be followed as instructed by the physician.

III. Factors Affecting Efficacy

CYP2C19 gene polymorphism: In poor metabolizers, the generation of active metabolite is reduced, the antiplatelet effect is weakened, and the risk of thrombosis is relatively increased; genetic testing may be performed when necessary.

Drug interactions: Avoid concomitant use with strong CYP2C19 inhibitors such as omeprazole and esomeprazole.

Adherence: Regular medication is key to ensuring efficacy; missed doses or unauthorized discontinuation can increase the risk of thrombotic events.

IV. Safety and Monitoring

Bleeding risk: Gum bleeding and subcutaneous ecchymosis are common; severe cases may include gastrointestinal or intracranial bleeding, and close observation is required during medication.

Contraindicated populations: Use is contraindicated or should be used with caution in patients with active bleeding, severe hepatic impairment, or allergy to this product.

Discontinuation before surgery: For elective surgery, the drug is generally stopped 5–7 days in advance; this must be evaluated by a physician, and the drug should not be stopped on one's own.