title: Detection of small inhibitory effects of acetylsalicylic acid (ASA) by platelet impedance aggregometry in whole blood.
abstract: Our investigations have demonstrated on 10 volunteers receiving either 500 mg or 100 mg acetylsalicylic acid (ASA) that a low collagen concentration (1 microgram/ml) can best detect the aggregation defect caused by ASA. With the impedance aggregometry the mean inhibition reaches 82% and 52% with 500 mg and 100 mg ASA, respectively. Collagen at higher concentration (3 micrograms/ml) as well as ADP 10 and 25 mumol/l are less sensitive, less than 25% inhibition was recorded. These results suggest that a 1 microgram/ml concentration of collagen is adequate for the control of the ASA effect up to 6 days after intake of 100 mg. Furthermore, the von Willebrand factor (vWF) dependent platelet aggregation induced by 0.6 and 1.0 mg/ml ristocetin was clearly diminished after ASA. Therefore, a ristocetin screening test in whole blood for vWF disorder is possibly distorted when the test is performed within 6 days from ASA administration.
authors.affiliation: Coagulation and Fibrinolysis Laboratory, Kantonsspital, Basel, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Sathiropas
authors.forename: G A
authors.initials: GA
authors.lastname: Marbet
authors.forename: S
authors.initials: S
authors.lastname: Sahaphong
authors.forename: F
authors.initials: F
authors.lastname: Duckert
mesh_terms: D000328:Adult; D000368:Aged; D001241:Aspirin / Q000494:pharmacology*; D003094:Collagen / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D012310:Ristocetin / Q000494:pharmacology
chemical_list: D010975:Platelet Aggregation Inhibitors; D012310:Ristocetin; D003094:Collagen; D001241:Aspirin