title: Effects of PEG-hirudin in clotting parameters and platelet function and its interaction with aspirin in healthy volunteers.
abstract: The purpose of this study was to investigate the pharmacodynamics of PEG-Hirudin and its potential interactions with acetylsalicylic acid (ASA 325 mg once daily from days 1-3). In a randomized, 2-way cross-over trial, 6 healthy volunteers received PEG-Hirudin (i.v. bolus of 0.2 mg/kg + 0.02 mg/kg/h for 24 hours) and placebo (i.v. bolus + 24-hour infusion). In a further randomized, 3-way cross-over trial another 9 healthy volunteers received ASA (325 mg) or oral placebo from days 1 to 3 and PEG-Hirudin (0.2 mg/kg + 0.02 mg/kg/h for 24 h) or i.v. placebo on day 3. Assessments included bleeding time (BT), collagen (1 microgram ml(-1))-induced platelet aggregation (CIPA), platelet adhesion, ecarin clotting time (ECT), activated clotting time (ACT), plasma anti-factor IIa activity (aIIa), and activated partial thromboplastin time (aPTT). Ten minutes after the PEG-Hirudin injection/starting the infusion, mean plasma concentration was 3.1 microgram/mL and aPTT, ECT, and ACT were prolonged up to 80, 309, and 233 seconds, respectively. During the last 8 hours of the 24-hour infusion mean PEG-Hirudin plasma concentration was 1.3 microgram/mL. In the interaction study, ASA significantly inhibited CIPA. At 6 hours after administration, on day 3 mean BT was 6.5 minutes after PEG-Hirudin alone, 18.2 minutes after ASA alone, and 32.9 minutes after combined administration of ASA and PEG-Hirudin. PEG-Hirudin (0.2 mg/kg + 0.02 mg/kg/h for 24 hours) administered alone or together with 325 mg ASA proved to be safe in healthy volunteers. Combined use of PEG-Hirudin and ASA significantly increased the mean bleeding time compared to ASA or PEG-Hirudin monodrug administration. None of the clotting parameters or platelet function tests correlated with the prolongation of the bleeding time.
authors.affiliation: Abbott GmbH & Co. KG, Ludwigshafen, Germany. hans-ulrich.esslinger@abbott.com
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Esslinger
authors.forename: Stephan
authors.initials: S
authors.lastname: Köhne
authors.forename: Piotr
authors.initials: P
authors.lastname: Radziwon
authors.forename: Jeanine M
authors.initials: JM
authors.lastname: Walenga
authors.forename: Hans Klaus
authors.initials: HK
authors.lastname: Breddin
mesh_terms: D001241:Aspirin / Q000494:pharmacology*; D001760:Bleeding Time; D001777:Blood Coagulation / Q000187:drug effects*; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology*; D018592:Cross-Over Studies; D006629:Hirudins / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology*; D006801:Humans; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D012016:Reference Values
chemical_list: D006629:Hirudins; D010975:Platelet Aggregation Inhibitors; C104614:polyethyleneglycol-hirudin; D001241:Aspirin