Bivalirudin
An approved intravenous anticoagulant used during coronary intervention. Derived from leech saliva chemistry, with a very short and predictable action.
Cardiovascular & Blood
Eptifibatide
A cyclic heptapeptide antiplatelet drug modelled on rattlesnake venom, used intravenously during coronary intervention and in acute coronary syndromes.
Overview
The final common step in platelets clumping together is a receptor called GPIIb/IIIa grabbing fibrinogen and bridging one platelet to the next. Block that receptor and platelets cannot aggregate no matter what activated them. Eptifibatide is built around a sequence found in barbourin, a protein in the venom of the southeastern pygmy rattlesnake, which happens to block this receptor with unusual selectivity.
A cyclic heptapeptide containing a KGD (Lys-Gly-Asp) motif derived from barbourin, a disintegrin from Sistrurus miliarius barbouri venom. The KGD sequence confers selectivity for integrin αIIbβ3 (GPIIb/IIIa) over the closely related αvβ3 vitronectin receptor, which the more common RGD motif does not. Competitive, reversible inhibition of fibrinogen and von Willebrand factor binding blocks the final common pathway of platelet aggregation. Platelet function recovers within 4–8 hours of stopping the infusion. Renally cleared, requiring dose reduction in impairment.
Research areas
Acute coronary syndromePercutaneous coronary interventionPlatelet biology
Dosing reported in the literature
Every protocol below is reproduced from a published study or approved labelling, with its source named. These are records of what was studied — not recommendations, and not a suggestion that any of them is appropriate for any person.
| Protocol as reported | Source |
|---|---|
| 180 mcg/kg intravenous bolus followed by 2 mcg/kg/min infusion until hospital discharge or up to 72 hours | Approved product labelling |
| Double 180 mcg/kg bolus 10 minutes apart plus infusion in the PCI setting | ESPRIT, The Lancet 2000 |
Trial status
Large completed phase 3 trials including PURSUIT and ESPRIT.
Reported safety signals
- Bleeding is the principal risk, particularly at vascular access sites.
- Thrombocytopenia can occur, occasionally profound; platelet count should be checked within hours of starting.
- Renal clearance requires infusion rate reduction in impairment and avoidance in dialysis dependence.
- Contraindicated with recent major surgery, stroke, or active bleeding.
Common questions
Why is a snake venom peptide safer than a synthetic RGD compound?
The KGD motif in barbourin, which eptifibatide copies, binds the platelet receptor αIIbβ3 selectively. The more common RGD motif also binds αvβ3 on endothelium and other tissues, which broadens the effect in unwanted ways. Evolution solved the selectivity problem before chemists did.
Primary sources
Medical disclaimer
This page is for informational and research purposes only. Nothing here constitutes medical advice. The compounds discussed are research chemicals. Consult a qualified clinician before starting any protocol.
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