What is clopidogrel used for?

Clopidogrel Indications and Uses

Clopidogrel is primarily used to prevent blood clots in patients with cardiovascular disease, including those with recent myocardial infarction, stroke, peripheral arterial disease, and patients undergoing coronary stent placement. 1

Primary Indications

• Clopidogrel is indicated for patients with recent acute coronary syndrome (ACS), unstable angina, or non-Q-wave myocardial infarction, typically in combination with aspirin 75-100 mg 2
• It is recommended for patients with ST-elevation myocardial infarction (STEMI) regardless of whether they undergo reperfusion with fibrinolytic therapy or do not receive reperfusion therapy 3
• Clopidogrel is an effective antiplatelet therapy for patients with symptomatic atherosclerotic lower extremity peripheral arterial disease 2, 1
• It is indicated for patients with recent ischemic stroke or transient ischemic attack (TIA) to prevent recurrent events 2, 1

Mechanism of Action

• Clopidogrel is a thienopyridine that irreversibly binds to the platelet P2Y12 ADP receptor, inhibiting ADP-induced platelet activation 3
• It prevents platelets from sticking together and forming clots that can block arteries, working through a different mechanism than aspirin 1

Clinical Benefits

• In the CAPRIE trial, clopidogrel reduced the relative risk of myocardial infarction, ischemic stroke, or vascular death by 8.7% compared to aspirin in high-risk patients 3, 4
• For patients with acute coronary syndromes, the addition of clopidogrel to aspirin reduced the 9-month composite endpoint (cardiovascular mortality, nonfatal MI, and stroke) by 20% compared with aspirin therapy alone 3
• In the COMMIT-CCS-2 trial involving STEMI patients, clopidogrel plus aspirin reduced the composite primary endpoint of death, reinfarction, or stroke from 10.1% to 9.2% compared to placebo plus aspirin 3
• The CLARITY-TIMI 28 study showed that clopidogrel reduced the risk of an occluded infarct artery on angiography or death or recurrent MI before angiography from 21.7% to 15.0% in patients receiving fibrinolytic therapy 3

Dosing Considerations

• Standard maintenance dose is 75 mg once daily 1
• For patients under 75 years of age with STEMI receiving fibrinolytic therapy or no reperfusion therapy, a 300 mg loading dose is reasonable 3
• Treatment duration should continue for at least 14 days after STEMI, though long-term maintenance therapy (e.g., 1 year) is reasonable 3
• For patients undergoing coronary artery bypass grafting (CABG), clopidogrel should be withheld for at least 5 days and preferably 7 days unless urgent revascularization outweighs bleeding risks 3

Safety Considerations

• Clopidogrel can cause bleeding which can be serious and sometimes fatal 1
• Patients taking clopidogrel may bruise and bleed more easily, experience more frequent nosebleeds, and have prolonged bleeding time 1
• Thrombotic Thrombocytopenic Purpura (TTP) is a rare but serious adverse effect that can occur after initiating clopidogrel therapy, typically within the first 2 weeks of treatment 3
• Clopidogrel has a better safety profile than ticlopidine, with fewer side effects and less required monitoring 2

Drug Interactions

• Concomitant use with proton pump inhibitors, particularly omeprazole and esomeprazole, may reduce clopidogrel's effectiveness 1
• Increased bleeding risk when combined with aspirin, NSAIDs, warfarin, SSRIs, or SNRIs 1
• No significant interactions with commonly used cardiovascular drugs were observed in clinical trials 5

Specific Patient Populations

• Clopidogrel is preferred over ticagrelor in patients with high bleeding risk 3
• While prasugrel and ticagrelor provide stronger platelet inhibition in ACS patients, they also increase bleeding risk compared to clopidogrel 3
• No dose adjustment is necessary based on gender, weight, race, or in patients with renal impairment or mild-to-moderate hepatic impairment 5

Common Pitfalls and Caveats

• Patients should not discontinue clopidogrel without consulting their healthcare provider, as premature discontinuation increases risk of heart attack or death 1
• Patients should inform all healthcare providers, including dentists, about clopidogrel use before any surgery or invasive procedure 1
• Genetic factors can affect how the body metabolizes clopidogrel, potentially reducing its effectiveness in some patients 1
• Significant interpatient variability exists in pharmacodynamic response to clopidogrel 3