What is the recommended dosage and duration of Plavix (clopidogrel) for post-surgical antiplatelet therapy?

Post-Surgical Plavix (Clopidogrel) Dosing and Duration

For patients undergoing coronary artery bypass grafting (CABG), aspirin should be started within 6 hours after surgery at 100-325 mg daily for 1 year, while clopidogrel 75 mg daily should be resumed postoperatively and continued to complete 12 months of dual antiplatelet therapy (DAPT) if the patient had acute coronary syndrome (ACS). 1

Post-CABG Antiplatelet Management

Aspirin Initiation

• Start aspirin within 6 hours after CABG to reduce saphenous vein graft closure 1
• Dosing: 100-325 mg daily for the first year, then continue indefinitely at 75-162 mg daily 1
• The 2006 guidelines allowed up to 48 hours for initiation, but the 2011 update shortened this to 6 hours based on improved evidence 1

Clopidogrel Resumption After CABG

For ACS patients (STEMI or NSTE-ACS):

• Resume clopidogrel 75 mg daily after CABG as soon as deemed safe postoperatively 1
• Continue for a total of 12 months from the ACS event 1
• No additional loading dose is needed if the patient was already on clopidogrel pre-operatively 1

For non-ACS patients with prior stent placement:

• Drug-eluting stent (DES): Resume clopidogrel 75 mg daily postoperatively and continue for at least 12 months total from stent placement 1
• Bare-metal stent (BMS): Resume clopidogrel 75 mg daily and continue for minimum 1 month, ideally up to 12 months from stent placement 1

For stable coronary disease without recent ACS or stent:

• Clopidogrel 75 mg daily can be used as an alternative to aspirin if aspirin is contraindicated or not tolerated 1
• No loading dose required; maintenance dose only 2

Timing of Clopidogrel Discontinuation Before Elective Surgery

Critical safety consideration: Premature discontinuation of clopidogrel increases cardiovascular event risk, but continuing it perioperatively increases bleeding risk 2

• Discontinue clopidogrel at least 5 days before elective surgery with major bleeding risk 1, 2
• For ticagrelor: stop at least 3 days before surgery 1
• For prasugrel: stop at least 7 days before surgery 1
• Continue low-dose aspirin (75-100 mg daily) throughout the perioperative period unless contraindicated 1

Post-PCI (Non-Surgical) DAPT Duration

For ACS patients after PCI with stent:

• Clopidogrel 75 mg daily (or prasugrel 10 mg daily, or ticagrelor 90 mg twice daily) for at least 12 months 1
• Loading dose: 300-600 mg clopidogrel for ACS patients 1
• After fibrinolytic therapy: 300 mg loading dose if given within 24 hours, 600 mg if given >24 hours after fibrinolysis 1

For stable patients after DES (non-ACS):

• Clopidogrel 75 mg daily for at least 12 months if not at high bleeding risk 1

For stable patients after BMS (non-ACS):

• Clopidogrel 75 mg daily for minimum 1 month, ideally up to 12 months (minimum 2 weeks if high bleeding risk) 1

Extended DAPT Beyond 12 Months

May be reasonable in select patients who:

• Have tolerated DAPT without bleeding complications 1
• Are not at high bleeding risk (no prior bleeding on DAPT, no coagulopathy, no oral anticoagulant use) 1
• Have high ischemic risk (prior MI, complex lesions, diabetes) 1

However, this is a Class IIb recommendation (may be reasonable, not strongly recommended) and requires careful bleeding risk assessment 1

Common Pitfalls to Avoid

• Do not delay aspirin after CABG: The 6-hour window is critical for graft patency 1
• Do not give loading doses of clopidogrel immediately post-CABG: Resume maintenance dose (75 mg daily) only, as loading doses increase bleeding risk 1
• Do not stop DAPT prematurely in ACS patients: This dramatically increases stent thrombosis risk (HR 13.74) 3
• Do not use higher aspirin doses long-term: After initial post-PCI period, reduce to 75-100 mg daily to minimize bleeding 1
• Avoid combining clopidogrel with omeprazole or esomeprazole: These strong CYP2C19 inhibitors reduce clopidogrel effectiveness 2

Special Populations

CYP2C19 poor metabolizers:

• Consider alternative P2Y12 inhibitor (prasugrel or ticagrelor) as clopidogrel may be less effective 2
• Genetic testing is available if clinical response is uncertain 2

High bleeding risk patients:

• May discontinue P2Y12 inhibitor after 6 months if developed high bleeding risk or significant bleeding 1
• Requires careful risk-benefit assessment 1