title: Antiplatelet effect of 50-mg maintenance dose of clopidogrel compared to 200 mg ticlopidine: a preliminary study.
abstract: In the United States and Europe, patients with coronary stents are maintained on 75 mg clopidogrel. Because the maintenance dose of ticlopidine in patients with coronary stents is 100 mg twice daily in Japan and 250 mg twice daily in the United States and Europe, in Japanese patients a lower dose of clopidogrel may achieve an antiplatelet effect comparable to 200 mg ticlopidine. Platelet aggregation was evaluated in 104 consecutive patients on 50 mg clopidogrel plus aspirin (n = 54) and 200 mg ticlopidine plus aspirin (n = 50). Platelets were stimulated with adenosine diphosphate (5 and 20 mumol/l) and aggregation was assessed by optical aggregometry. There was no significant difference in platelet aggregation induced with 5 (37% +/- 11% vs 38% +/- 15%, not significant) and 20 mumol/l adenosine diphosphate (48% +/- 13% vs 51% +/- 12%, not significant) between 50 mg clopidogrel and 200 mg ticlopidine. In Japanese patients, there is the possibility that a maintenance dose of 50 mg clopidogrel on platelet inhibition is comparable to 200 mg ticlopidine.
authors.affiliation: Department of Cardiovascular Science and Medicine, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Fukushima
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Kitahara
authors.forename: Yo
authors.initials: Y
authors.lastname: Iwata
authors.forename: Nakabumi
authors.initials: N
authors.lastname: Kuroda
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ooyama
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Kuwabara
authors.forename: Fumio
authors.initials: F
authors.lastname: Nomura
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
mesh_terms: D000244:Adenosine Diphosphate; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000295:instrumentation; D044466:Asian People; D000077144:Clopidogrel; D003324:Coronary Artery Disease / Q000097:blood / Q000208:ethnology / Q000628:therapy*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage*; D015607:Stents; D013927:Thrombosis / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D013988:Ticlopidine / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000244:Adenosine Diphosphate; D000077144:Clopidogrel; D013988:Ticlopidine