OBJECTIVES: We determined the effect of clopidogrel dosing on the incidence of nonresponsiveness (NR) and high post-treatment platelet aggregation (post-PA). BACKGROUND: We have reported NR after a 300-mg loading dose. Limited information is available on the comparative effect of a 600-mg loading dose on the incidence of NR and high post-PA. METHODS:Clopidogrel responsiveness and post-PA were measured in patients undergoing stenting (n = 190) randomly treated with either a 300-mg or a 600-mg clopidogrel load. Nonresponsiveness was defined as <10% absolute change in platelet aggregation, and high post-PA was defined as >75th percentile aggregation after 300 mg clopidogrel. RESULTS:Nonresponsiveness was lower after 600 mg compared to the 300-mg dose (8% vs. 28% and 8% vs. 32% with 5 and 20 microM ADP, respectively, p < 0.001). Among the patients with high post-PA after 300 mg clopidogrel, 62% to 65% had NR, whereas after the 600-mg dose, all of the patients with high post-PA had NR. CONCLUSIONS: A 600-mg clopidogrel loading dose reduces the incidence of NR and high post-PA as compared to a 300-mg dose. Higher dosing strategies and methods to confirm platelet inhibition should be further investigated in order to optimally use clopidogrel in patients undergoing stenting.
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OBJECTIVES: We determined the effect of clopidogrel dosing on the incidence of nonresponsiveness (NR) and high post-treatment platelet aggregation (post-PA). BACKGROUND: We have reported NR after a 300-mg loading dose. Limited information is available on the comparative effect of a 600-mg loading dose on the incidence of NR and high post-PA. METHODS:Clopidogrel responsiveness and post-PA were measured in patients undergoing stenting (n = 190) randomly treated with either a 300-mg or a 600-mg clopidogrel load. Nonresponsiveness was defined as <10% absolute change in platelet aggregation, and high post-PA was defined as >75th percentile aggregation after 300 mg clopidogrel. RESULTS: Nonresponsiveness was lower after 600 mg compared to the 300-mg dose (8% vs. 28% and 8% vs. 32% with 5 and 20 microM ADP, respectively, p < 0.001). Among the patients with high post-PA after 300 mg clopidogrel, 62% to 65% had NR, whereas after the 600-mg dose, all of the patients with high post-PA had NR. CONCLUSIONS: A 600-mg clopidogrel loading dose reduces the incidence of NR and high post-PA as compared to a 300-mg dose. Higher dosing strategies and methods to confirm platelet inhibition should be further investigated in order to optimally use clopidogrel in patients undergoing stenting.
Authors: L Součková; R Opatřilová; P Suk; I Čundrle; M Pavlík; V Zvoníček; O Hlinomaz; V Šrámek Journal: Eur J Clin Pharmacol Date: 2012-08-14 Impact factor: 2.953
Authors: J P Lewis; A S Fisch; K Ryan; J R O'Connell; Q Gibson; B D Mitchell; H Shen; K Tanner; R B Horenstein; R Pakzy; U S Tantry; K P Bliden; P A Gurbel; A R Shuldiner Journal: Clin Pharmacol Ther Date: 2011-08-31 Impact factor: 6.875
Authors: Rikke Sørensen; G H Gislason; E L Fosbøl; S Rasmussen; L Køber; J K Madsen; C Torp-Pedersen; S Z Abildstrom Journal: Br J Clin Pharmacol Date: 2008-09-23 Impact factor: 4.335
Authors: Rakesh K Sharma; Hanumanth K Reddy; Vibhuti N Singh; Rohit Sharma; Donald J Voelker; Girish Bhatt Journal: Vasc Health Risk Manag Date: 2009-11-16