A double-blind, randomized study on platelet aggregation in patients treated with a daily dose of 150 or 75 mg of clopidogrel for 30 days.
OBJECTIVE
We sought to test whether an increase in the clopidogrel maintenance dose results in increased inhibition of platelet aggregation.


RESULTS
Sixty patients after pre-treatment with 600 mg of clopidogrel and within 12 h after successful PCI were included in this trial. They were allocated to receive one of two clopidogrel daily maintenance doses (75 or 150 mg) for 30 days in a double-blind randomized manner. Platelet function was evaluated 30 days after the intervention with optical aggregometry and with a new point-of-care test (VerifyNowtrade mark P2Y12 assay). Maximal 5 microM ADP-induced platelet aggregation 30 days after PCI in the group treated with 150 mg/day clopidogrel (45.1 +/- 20.9%) was significantly lower than in the group treated with 75 mg/day (65.3 +/- 12.1%; P < 0.001). The VerifyNowtrade mark P2Y12 assay also indicated a higher degree of platelet function inhibition in the group treated with 150 mg/day (60.0 +/- 72.0 P2Y12 Reaction Units) than in the group treated with 75 mg/day (117.0 +/- 64.3 P2Y12 Reaction Units; P = 0.004).


CONCLUSIONS
Administration of a 150 mg oral maintenance dose of clopidogrel results in more intense inhibition of platelet aggregation than administration of the currently recommended 75 mg maintenance dose.
von Beckerath
Nicolas
N
Deutches Herzzentrum, Technische Universitat Munchen, Munich, Germany. beckerath.@dhm.mhn.de
Kastrati
Adnan
A
Wieczorek
Anna
A
Pogatsa-Murray
Gisela
G
Sibbing
Dirk
D
Graf
Isolde
I
Schömig
Albert
A
D000368:Aged; D000077144:Clopidogrel; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D010979:Platelet Function Tests; D013923:Thromboembolism / Q000188:drug therapy*; D013927:Thrombosis / Q000188:drug therapy*; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use
D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine