Class: Platelet Aggregation Inhibitor
Dosage Forms. Tablet: 75 mg, 300 mg
Common FDA Label Indication, Dosing, and Titration.
1. Acute ST and non-ST segment elevation myocardial infarction: 300-600 mg po loading dose, followed by 75 mg po daily in combination with aspirin
2. Thrombosis prevention in arteriosclerotic vascular disease, following stroke, in peripheral arterial occlusive disease: 75 mg po daily
1. Thrombosis prevention in atrial fibrillation or following percutaneous coronary intervention: 75 mg po daily in combination with aspirin
MOA. Clopidogrel is an antiplatelet agent that prevents platelet aggregation by direct inhibition of ADP binding to receptor sites, inhibiting subsequent activation of the glycoprotein IIb/IIIa complex. This action is irreversible; therefore, platelets exposed to clopidogrel are inhibited for their life spans.
Drug Characteristics: Clopidrogrel
Medication Safety Issues: Clopidrogrel
Drug Interactions: Clopidrogrel
Adverse Reactions: Clopidrogrel
Efficacy Monitoring Parameters. Prevention of thrombotic events.
Toxicity Monitoring Parameters. Signs/symptoms of bleeding, especially with concomitant anticoagulant therapy.
Key Patient Counseling Points. Report signs/symptoms of bleeding, especially if used concomitantly with anticoagulant therapy. Do not stop therapy abruptly without first talking with prescriber to minimize the risk of re-thrombosis, particularly after stent placement. Clopidogrel should be discontinued 5 d prior to elective surgery, if an antiplatelet effect is not desired.
Clinical Pearls. Safety and efficacy not established in pediatric patients. Clopidogrel effectiveness is dependent on its activation to an active metabolite by CYP2C19. In patients who are CYP2C19 poor metabolizers, clopidogrel at recommended doses forms less of the active metabolite and has a smaller effect on platelet function. Compared with normal metabolizers, poor CYP2C19 metabolizers with acute coronary syndrome, or undergoing percutaneous coronary intervention treated with clopidogrel at recommended doses, exhibit higher cardiovascular event rates. Consider alternative treatment or a higher dose in CYP2C19 poor metabolizers.