Pharmacodynamic Study on Efficacy of Clopidogrel With St. John's Wort

Summary

The purpose of this study is to evaluate whether patients post PCI receiving clopidogrel who are carriers of at least one CYP 2C19 loss-of-function allele may achieve improved pharmacodynamic efficacy of clopidogrel when treated with the CYP 2C19 enzyme inducing agent, St. John's wort, as compared with placebo. Hypothesis 1. Reduced platelet reactivity is present in patients receiving St. John's wort as compared to placebo when utilized in combination with clopidogrel 2. The combination or St. John's wort and clopidogrel results in enhanced platelet inhibition

Timeline

Start

2011-04

Primary completion

2015-03

Completion

2015-03

Publications

• Background Yusuf S, Zhao F, Mehta SR, Chrolavicius S, Tognoni G, Fox KK; Clopidogrel in Unstable Angina to Prevent Recurrent Events Trial Investigators. Effects of clopidogrel in addition to aspirin in patients with acute coronary syndromes without ST-segment elevation. N Engl J Med. 2001 Aug 16;345(7):494-502. doi: 10.1056/NEJMoa010746.
• Background Steinhubl SR, Berger PB, Mann JT 3rd, Fry ET, DeLago A, Wilmer C, Topol EJ; CREDO Investigators. Clopidogrel for the Reduction of Events During Observation. Early and sustained dual oral antiplatelet therapy following percutaneous coronary intervention: a randomized controlled trial. JAMA. 2002 Nov 20;288(19):2411-20. doi: 10.1001/jama.288.19.2411.
• Background Bhatt DL, Fox KA, Hacke W, Berger PB, Black HR, Boden WE, Cacoub P, Cohen EA, Creager MA, Easton JD, Flather MD, Haffner SM, Hamm CW, Hankey GJ, Johnston SC, Mak KH, Mas JL, Montalescot G, Pearson TA, Steg PG, Steinhubl SR, Weber MA, Brennan DM, Fabry-Ribaudo L, Booth J, Topol EJ; CHARISMA Investigators. Clopidogrel and aspirin versus aspirin alone for the prevention of atherothrombotic events. N Engl J Med. 2006 Apr 20;354(16):1706-17. doi: 10.1056/NEJMoa060989. Epub 2006 Mar 12.
• Background Kimura T, Morimoto T, Kozuma K, Honda Y, Kume T, Aizawa T, Mitsudo K, Miyazaki S, Yamaguchi T, Hiyoshi E, Nishimura E, Isshiki T; RESTART Investigators. Comparisons of baseline demographics, clinical presentation, and long-term outcome among patients with early, late, and very late stent thrombosis of sirolimus-eluting stents: Observations from the Registry of Stent Thrombosis for Review and Reevaluation (RESTART). Circulation. 2010 Jul 6;122(1):52-61. doi: 10.1161/CIRCULATIONAHA.109.903955. Epub 2010 Jun 21.
• Background Savi P, Herbert JM, Pflieger AM, Dol F, Delebassee D, Combalbert J, Defreyn G, Maffrand JP. Importance of hepatic metabolism in the antiaggregating activity of the thienopyridine clopidogrel. Biochem Pharmacol. 1992 Aug 4;44(3):527-32. doi: 10.1016/0006-2952(92)90445-o.
• Background Mega JL, Close SL, Wiviott SD, Shen L, Hockett RD, Brandt JT, Walker JR, Antman EM, Macias W, Braunwald E, Sabatine MS. Cytochrome p-450 polymorphisms and response to clopidogrel. N Engl J Med. 2009 Jan 22;360(4):354-62. doi: 10.1056/NEJMoa0809171. Epub 2008 Dec 22.
• Background Simon T, Verstuyft C, Mary-Krause M, Quteineh L, Drouet E, Meneveau N, Steg PG, Ferrieres J, Danchin N, Becquemont L; French Registry of Acute ST-Elevation and Non-ST-Elevation Myocardial Infarction (FAST-MI) Investigators. Genetic determinants of response to clopidogrel and cardiovascular events. N Engl J Med. 2009 Jan 22;360(4):363-75. doi: 10.1056/NEJMoa0808227. Epub 2008 Dec 22.
• Background Wang LS, Zhu B, Abd El-Aty AM, Zhou G, Li Z, Wu J, Chen GL, Liu J, Tang ZR, An W, Li Q, Wang D, Zhou HH. The influence of St John's Wort on CYP2C19 activity with respect to genotype. J Clin Pharmacol. 2004 Jun;44(6):577-81. doi: 10.1177/0091270004265642.
• Background Barnes PM, Powell-Griner E, McFann K, Nahin RL. Complementary and alternative medicine use among adults: United States, 2002. Adv Data. 2004 May 27;(343):1-19.
• Background Wang LS, Zhou G, Zhu B, Wu J, Wang JG, Abd El-Aty AM, Li T, Liu J, Yang TL, Wang D, Zhong XY, Zhou HH. St John's wort induces both cytochrome P450 3A4-catalyzed sulfoxidation and 2C19-dependent hydroxylation of omeprazole. Clin Pharmacol Ther. 2004 Mar;75(3):191-7. doi: 10.1016/j.clpt.2003.09.014.
• Background Lau W, Carville D, Guyer K, Neer C. St. John's wort enhances the platelet inhibitor effect of clopidogrel in clopidogrel "resistant" healthy volunteers. J Am Coll Cardiol 2005;4:382A(abstract).
• Background Lau WC, Welch TD, Shields T, Rubenfire M, Tantry US, Gurbel PA. The effect of St John's Wort on the pharmacodynamic response of clopidogrel in hyporesponsive volunteers and patients: increased platelet inhibition by enhancement of CYP3A4 metabolic activity. J Cardiovasc Pharmacol. 2011 Jan;57(1):86-93. doi: 10.1097/FJC.0b013e3181ffe8d0.

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