Clopidogrel

Generic name: Clopidogrel

Drug class: Platelet aggregation inhibitors

Dosage form: Oral tablet (75 mg, 300 mg)

Root of administration: Oral

Dose: For acute coronary syndrome or myocardial infarction: 300 mg loading dose, followed by 75 mg daily. For stroke or peripheral arterial disease: 75 mg daily. Dosage may vary based on individual patient factors and clinical response.

Mechanism of action: Clopidogrel is a prodrug that, after hepatic metabolism, irreversibly inhibits the P2Y₁₂ subtype of the ADP receptor on platelets, preventing ADP-mediated activation of the glycoprotein IIb/IIIa complex, thereby inhibiting platelet aggregation and reducing thrombus formation.

Drug usage cases:

• Prevention of atherosclerotic events in patients with a history of myocardial infarction, stroke, or peripheral arterial disease.
• Acute coronary syndrome, including unstable angina and non-ST elevation myocardial infarction.
• Post-percutaneous coronary intervention (PCI) with stent placement to prevent stent thrombosis.
• Secondary prevention of ischemic stroke.
• Management of acute ischemic stroke in combination with aspirin.

Drug contraindications:

• Active bleeding disorders, such as peptic ulcer disease or intracranial hemorrhage.
• Hypersensitivity to clopidogrel or any component of the formulation.
• Severe hepatic impairment.
• Concurrent use with omeprazole or esomeprazole due to potential drug interactions affecting clopidogrel’s efficacy.

Side effects:

• Common: Headache, dizziness, abdominal pain, nausea, diarrhea, rash, pruritus.
• Serious: Bleeding complications (e.g., gastrointestinal bleeding, intracranial hemorrhage), thrombotic thrombocytopenic purpura (TTP), neutropenia, agranulocytosis, liver enzyme abnormalities, hypersensitivity reactions (e.g., angioedema, anaphylaxis).

Warnings:

• Increased risk of bleeding; monitor for signs of bleeding and manage appropriately.
• Discontinue at least 5 days prior to elective surgery to reduce bleeding risk.
• Use with caution in patients with a history of gastrointestinal bleeding or ulcers.
• Monitor for signs of TTP, a rare but serious condition characterized by thrombocytopenia, hemolytic anemia, neurologic abnormalities, and renal dysfunction.
• Potential drug interactions with proton pump inhibitors (e.g., omeprazole, esomeprazole) that may reduce clopidogrel’s effectiveness; consider alternative medications.
• Monitor liver function tests periodically during therapy.

Use during pregnancy or breastfeeding: Clopidogrel is classified as pregnancy category B1 in Australia, indicating no evidence of harm in animal studies but lack of well-controlled human studies. Its safety during pregnancy has not been well established. Clopidogrel is excreted in human milk; caution is advised when administering to breastfeeding women. Consult a healthcare provider to assess potential risks and benefits before use during pregnancy or lactation.