Elevating local concentrations of GPIIb-IIIa antagonists counteracts platelet thrombus stability
Pharmacology study published in Journal of Thrombosis and Thrombolysis (2013)
Abstract
Glycoprotein IIb-IIIa (GPIIb-IIIa) antagonists have the capacity to destabilize coronary thrombi and restore vessel patency. Antagonist concentration and residence time, which can be increased by local intracoronary (LIC) administration, and thrombus age may be key factors that influence thrombus stability. Light transmission aggregometry was used to examine the effects of exposing human platelet aggregates to extremely high local levels of GPIIb-IIIa antagonists versus conventional therapeutic levels in vitro. Freshly-formed or aged platelet aggregates were subjected to GPIIb-IIIa antagonists (abciximab, eptifibatide) or direct thrombin inhibitor bivalirudin at concentrations simulating either conventional intravenous (IV) or LIC administration. The degree of antagonist-induced disaggregation was significantly higher using elevated (LIC) doses versus conventional (IV) doses (60.1 % vs. 7.4 % for abciximab, 41.6 % or 45.3 % vs. 17.6 % for eptifibatide, p < 0.01). Bivalirudin did not promote disaggregation. Microscopy confirmed noticeably smaller, more dispersed aggregates for antagonist LIC treatments. Dosing at LIC levels also induced more disaggregation than IV levels when aggregates were aged for 30 min prior to exposure. An in vitro perfusion model was used to simulate the fluid dynamics of IV or LIC administration of abciximab using a microporous local drug delivery balloon catheter such as the Atrium ClearWay™ RX. The perfusion model resulted in more rapid thrombus clearance with LIC dosing levels compared to IV. In summary, boosting the concentration of GPIIb-IIIa antagonists enhances dispersal of human platelet aggregates in vitro. These data provide a foundation for investigating increased local concentrations of GPIIb-IIIa antagonists in patients, as with LIC administration.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Local intracoronary versus IV doses of GPIIb-IIIa antagonists (abciximab, eptifibatide) caused 60.1% vs 7.4% disaggregation of platelet aggregates; bivalirudin (hirudin-class) did not promote disaggregation but is suitable as a thrombin inhibitor adjunct.
Por qué esto importa para la hirudoterapia
Este estudio in vitro examinó si la elevación de las concentraciones locales de antagonistas de GPIIb-IIIa (abciximab, eptifibatida) en comparación con los niveles de dosis intravenosa convencional podía desestabilizar agregados plaquetarios humanos; también se evaluó bivalirudina como comparador. Las concentraciones locales elevadas de antagonistas de GPIIb-IIIa produjeron una desagregación significativamente mayor (p. ej., 60,1 % frente a 7,4 % para abciximab, P<0,01), mientras que la bivalirudina no promovió la desagregación a ninguna de las concentraciones evaluadas. No existe una conexión defendible con la sanguijuela para el ámbito de la ASH: el resumen menciona la bivalirudina como inhibidor directo de la trombina pero no hace referencia a hirudina, sanguijuelas ni hirudoterapia. El estudio está limitado por su diseño in vitro utilizando agregados plaquetarios humanos y un modelo de perfusión simulado; no se presentan datos de eficacia in vivo ni clínica.
Citación
Elevating local concentrations of GPIIb-IIIa antagonists counteracts platelet thrombus stability.
Speich HE et al. · Journal of Thrombosis and Thrombolysis, 2013
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026