title: Combined effects of melagatran and eptifibatide on platelet aggregation inhibition but not thrombin generation inhibition.
abstract: The aim of our study was to investigate the combined in vitro effects of melagatran and eptifibatide on platelet aggregation and thrombin generation under low and high coagulant challenge in tissue-factor-activated, platelet-rich plasma. Increasing amounts of melagatran dose-dependently decreased prothrombin fragment 1.2 and activated factor X values, and dose-dependently prolonged the lag phase until the onset of platelet aggregation. Eptifibatide exerted a dose-dependent anti-aggregating effect under both high and low coagulant challenge. The combination of melagatran and eptifibatide resulted in significant additive prolongation of the lag phase until the onset of platelet aggregation, which was more pronounced under low coagulant challenge. Under low, but not under high, coagulant challenge, the combination of melagatran and eptifibatide had a significant additive inhibitory effect on platelet aggregation. No additive effects on decreasing prothrombin fragment 1.2 and activated factor X values were observed with combined administration of the drugs. The present study demonstrates the additive effect of melagatran and eptifibatide on platelet aggregation inhibition and on prolongation of the lag phase until the onset of platelet aggregation.
authors.affiliation: Department of Pediatrics, Ludwig Boltzmann Research Institute for Pediatric Haemostasis and Thrombosis and Institute of Medical Chemistry and Pregl Laboratory, University of Graz, Austria. koestenbergerm@hotmail.com
authors.forename: Martin
authors.initials: M
authors.lastname: Koestenberger
authors.forename: Siegfried
authors.initials: S
authors.lastname: Gallistl
authors.forename: Gerhard
authors.initials: G
authors.lastname: Cvirn
authors.forename: Birgit
authors.initials: B
authors.lastname: Roschitz
authors.forename: Thomas
authors.initials: T
authors.lastname: Rehak
authors.forename: Bettina
authors.initials: B
authors.lastname: Leschnik
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Muntean
mesh_terms: D001384:Azetidines; D001596:Benzylamines; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D000077542:Eptifibatide; D015951:Factor Xa / Q000032:analysis; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D006801:Humans; D010446:Peptide Fragments / Q000032:analysis; D010455:Peptides / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011516:Prothrombin / Q000032:analysis; D013917:Thrombin / Q000096:biosynthesis*; D013925:Thromboplastin / Q000494:pharmacology
chemical_list: D001384:Azetidines; D001596:Benzylamines; D010446:Peptide Fragments; D010455:Peptides; D010975:Platelet Aggregation Inhibitors; C045879:prothrombin fragment 1.2; C109573:melagatran; D011516:Prothrombin; D013925:Thromboplastin; D013917:Thrombin; D015951:Factor Xa; D000077542:Eptifibatide; D005998:Glycine