[Modified platelet aggregation test in patients on ASA and/or clopidogrel].
Therapy with acetylsalicylic acid (ASA) and/or clopidogrel is used to achieve prophylactic inhibition of platelet aggregation in patients with arterial thrombosis. We examined if aggregometry can be used to see the effect of antiplatelet drugs (ASA 30, 50, 100, 300 mg/d, clopidogrel 75 mg/d or ASA 100 + clopidogrel 75 mg/d). A modified platelet aggregation test was used to investigate maximum aggregation in response to ADP, collagen, adrenalin and arachidonic acid. Reference values were established based on healthy individuals. We devised a simple scoring system for detection of inadequate platelet inhibition. Compared with the control group, we detected a significant delay of maximum aggregation in response to all agonists in patients on ASA and combination therapy ASA + clopidogrel. Patients on clopidogrel alone were found to have prolonged aggregation when induced with ADP, collagen and arachidonic acid. The failure rate to achieve adequate platelet inhibition on 100 mg/d ASA, 75 mg/d clopidogrel or combination therapy was 27%, 26% and 7%, respectively. Our results demonstrate that platelet inhibition in aggregometry is inadequate in many patients with arterial thrombosis.
Eder
C
C
Klinikum Löbau-Zittau, Klinik für Innere Medizin, Görlitzer Str. 8, 02763 Zittau. innere.zi@kllz.de
Funke
U
U
Schulze
M
M
Lutze
G
G
Zimmermann
M
M
Prasse
T
T
Töpfer
G
G
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000368:Aged; D016718:Arachidonic Acid / Q000494:pharmacology; D001241:Aspirin / Q000494:pharmacology* / Q000627:therapeutic use; D000077144:Clopidogrel; D003094:Collagen / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004837:Epinephrine / Q000494:pharmacology; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D012016:Reference Values; D013927:Thrombosis / Q000097:blood / Q000188:drug therapy*; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use
D010975:Platelet Aggregation Inhibitors; D016718:Arachidonic Acid; D000244:Adenosine Diphosphate; D003094:Collagen; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin; D004837:Epinephrine