Eptifibatide

Chemical Identity

Property	Value
Chemical Formula	C35H49N11O9S2
Molecular Weight	831.96 Da
CAS Number	188627-80-7
Peptide Class	Cyclic Heptapeptide
Sequence	Mpa-Har-Gly-Asp-Trp-Pro-Cys-NH2
Disulfide Bonds	1 (Mpa-Cys)

Structure

Eptifibatide (Integrilin) is a synthetic cyclic heptapeptide inspired by a disintegrin from the venom of the southeastern pygmy rattlesnake. It contains the KGD (Lys-Gly-Asp) sequence that mimics the RGD motif of fibrinogen, enabling competitive binding to the platelet GPIIb/IIIa receptor.

Mechanism of Action

Eptifibatide reversibly binds to the GPIIb/IIIa (integrin alphaIIbbeta3) receptor on activated platelets, blocking fibrinogen-mediated platelet cross-linking and aggregation. The KGD motif provides selectivity for GPIIb/IIIa over other integrins. Inhibition is dose-dependent and reversible within 4-8 hours of discontinuation.

Clinical Applications

• Acute coronary syndromes: Unstable angina and NSTEMI (PURSUIT trial)
• Percutaneous coronary intervention: Adjunct during and after PCI
• STEMI: Off-label with primary PCI
• High-risk PCI: Patients not pre-treated with P2Y12 inhibitors

Pharmacokinetics

• Half-life: 2.5 hours
• Onset: Rapid (within minutes)
• Protein binding: 25%
• Elimination: Renal (50% unchanged)
• Route: IV bolus + infusion
• Dose adjustment: Required in renal impairment (CrCl <50)

Safety and Side Effects

Bleeding (major 1-2%), thrombocytopenia (0.2%), and minor bleeding. Contraindicated in active bleeding, severe hypertension, recent surgery, and thrombocytopenia. Platelet monitoring recommended.

References

• The PURSUIT Trial Investigators (1998). Eptifibatide for acute coronary syndromes. New England Journal of Medicine, 339, 436-443.
• Scarborough, R.M., et al. (1993). Design of potent GP IIb-IIIa antagonists. Journal of Biological Chemistry, 268, 1066-1073.