What is the intravenous (IV) equivalent for Plavix (clopidogrel)?

IV Equivalent for Plavix (Clopidogrel)

There is no direct IV equivalent for clopidogrel, but IV glycoprotein IIb/IIIa inhibitors (tirofiban, eptifibatide, abciximab) or IV cangrelor serve as alternative parenteral antiplatelet agents when oral P2Y12 inhibitors cannot be administered.

Primary IV Alternatives

Cangrelor (Preferred P2Y12 Inhibitor)

• Cangrelor is the only IV P2Y12 inhibitor available and provides the most pharmacologically similar mechanism to clopidogrel 1
• Provides rapid, predictable, and profound platelet inhibition with onset within 10 minutes and restoration of platelet function within 1 hour of discontinuation 1
• May be reasonable in P2Y12 inhibitor-naïve patients undergoing PCI to reduce periprocedural ischemic events (Class IIb recommendation) 2, 1
• Particularly valuable when absorption of oral medications is impaired or patients cannot take oral medications 1
• In the CHAMPION PHOENIX trial, cangrelor significantly reduced death, MI, ischemia-driven revascularization, or stent thrombosis at 48 hours compared to clopidogrel 1
• Pooled meta-analysis demonstrated 41% reduction in stent thrombosis versus clopidogrel 1

GP IIb/IIIa Inhibitors (Different Mechanism)

These agents block the final common pathway of platelet aggregation but work through a different mechanism than clopidogrel:

Tirofiban:

• High-bolus dose: 25 mcg/kg IV bolus, then 0.15 mcg/kg/min infusion 2
• Reduce infusion by 50% if creatinine clearance <30 mL/min 2
• Platelet aggregation returns to near-baseline within 4-8 hours after cessation 3, 4
• Class IIa recommendation for selected patients undergoing PCI 2

Eptifibatide:

• Double bolus: 180 mcg/kg IV bolus, then 2 mcg/kg/min; second 180 mcg/kg bolus 10 minutes after first 2
• Reduce infusion by 50% if creatinine clearance <50 mL/min; avoid in hemodialysis patients 2
• Class IIa recommendation for selected patients undergoing PCI 2

Abciximab:

• 0.25 mg/kg IV bolus, then 0.125 mcg/kg/min (maximum 10 mcg/min) for 12 hours 2
• Class IIa recommendation for selected patients undergoing PCI 2
• May be considered for intracoronary administration (0.25 mg/kg bolus) 2

Clinical Context for Selection

When to Use Cangrelor

• P2Y12 inhibitor-naïve patients undergoing PCI 2, 1
• Patients unable to take or absorb oral medications 1
• Patients requiring CABG or surgery early after PCI when prolonged P2Y12 inhibitor discontinuation is unsafe 1
• Provides bridge to oral P2Y12 inhibitor therapy 1

When to Use GP IIb/IIIa Inhibitors

• For patients undergoing PCI, adding IV GP IIb/IIIa blocker is appropriate to reduce procedure-related thrombotic complications 2
• High-risk patients with STEMI undergoing primary PCI (Class IIa) 2
• Bail-out situations during PCI complications 2
• NSTE-ACS patients with high thrombotic risk undergoing early invasive strategy 2
• The benefit/risk profile is substantially uncertain for ACS patients not routinely scheduled for early revascularization 2

When NOT to Use These Agents

• GP IIb/IIIa inhibitors should be considered only for bail-out in elective stenting 2
• Pre-catheterization laboratory administration of GP IIb/IIIa inhibitors has only Class IIb recommendation 2
• Prasugrel contraindicated in patients with prior stroke/TIA (use alternative if IV needed) 2

Important Caveats

Bleeding Risk

• Major bleeding rates similar between cangrelor and clopidogrel, but minor bleeding more frequent with cangrelor 1
• GP IIb/IIIa inhibitors increase bleeding risk, particularly when combined with heparin 2
• Monitor hemoglobin and platelet counts daily during GP IIb/IIIa administration 2

Thrombocytopenia

• Thrombocytopenia (<90,000 cells/µL) occurs slightly more frequently with tirofiban than heparin alone 4
• Severe thrombocytopenia (<20,000/mL) observed in 0.2% of patients on GP IIb/IIIa inhibitors 2

Combination Therapy Considerations

• Both clopidogrel (or alternative P2Y12 inhibitor) and GP IIb/IIIa inhibitor should be given before angiography for high-risk, troponin-positive UA/NSTEMI patients 2
• For lower-risk, troponin-negative patients, either IV GP IIb/IIIa inhibitor or clopidogrel should be added to aspirin and anticoagulant before diagnostic angiography 2
• All regimens should include aspirin (162-325 mg loading dose) 2

Renal Dosing

• Tirofiban requires 50% dose reduction if creatinine clearance <30 mL/min 2, 3
• Eptifibatide requires 50% dose reduction if creatinine clearance <50 mL/min and should be avoided in hemodialysis 2
• Cangrelor dosing does not require renal adjustment 1