Clopidogrel (Plavix)
Clopidogrel is a thienopyridine approved for use in patients with acute coronary syndrome who are managed medically or with coronary revascularization. In addition, clopidogrel is indicated following myocardial infarction, stroke, or established peripheral arterial disease to reduce the risk of new myocardial infarction, ischemic stroke, and other vascular death.
Pharmacodynamics
Dosed as a once daily oral tablet, clopidogrel attains peak plasma concentration 1 h after dosage with a half-life of 7–8 h. Clopidogrel and certain proton pump inhibitors are dependent on the CYP2C19 hepatic enzyme for their metabolism. Because of this, the FDA (Food and Drug Administration) recommends against coadministration of clopidogrel and omeprazole or esomeprazole. There is limited data regarding the use of clopidogrel in renal or hepatic impairment; therefore, no dose adjustment is necessary in these populations.
Reversal Agents To date, there are no available reversal agents that can be used in the event of an acute bleed in patients on clopidogrel. Current guidelines state that blood products, such as fresh frozen plasma or cryoprecipitate are the primary agents of reversal. Several case reports have indicated potential reversal of clopidogrel with use of methylprednisolone and desmopressin.
Recommended Withholding Period Before Endoscopic Procedures
Clopidogrel should be discontinued 5–7 days before any procedure where therapeutic intervention is anticipated or planned.