title: 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.
abstract: 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.
authors.affiliation: Deutches Herzzentrum, Technische Universitat Munchen, Munich, Germany. beckerath.@dhm.mhn.de
authors.forename: Nicolas
authors.initials: N
authors.lastname: von Beckerath
authors.forename: Adnan
authors.initials: A
authors.lastname: Kastrati
authors.forename: Anna
authors.initials: A
authors.lastname: Wieczorek
authors.forename: Gisela
authors.initials: G
authors.lastname: Pogatsa-Murray
authors.forename: Dirk
authors.initials: D
authors.lastname: Sibbing
authors.forename: Isolde
authors.initials: I
authors.lastname: Graf
authors.forename: Albert
authors.initials: A
authors.lastname: Schömig
mesh_terms: 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
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine