Pharmacodynamic Study on Efficacy of Clopidogrel With St. John's Wort
NCT ID: NCT01330589
Last Updated: 2017-10-05
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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WITHDRAWN
NA
INTERVENTIONAL
2011-04-30
2015-03-31
Brief Summary
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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
Detailed Description
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Specific Aims
1. To identify the difference in platelet reactivity in patients receiving St. John's wort or placebo
2. To characterize the difference in platelet inhibition in patients receiving St. John's wort or 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
Study Design The study is a prospective, randomized, double-blind, placebo-controlled, cross-over study of patients post PCI who require dual-antiplatelet therapy with aspirin and clopidogrel. Approximately 84 patients will be enrolled and undergo pharmacogenetic testing to assess clopidogrel responsiveness utilizing CYP P450 2C19 genotyping (Plavitest®). Based upon an assumption of 30% genetic non-responsiveness and a dropout rate of 20%, to achieve a final sample size of 20 subjects in the randomized crossover portion of the study, the investigators need to enroll approximately 84 subjects. Patients identified as carriers of at least one CYP 2C19 loss-of-function allele (i.e. clopidogrel reduced-metabolizers) will remain in the study and be randomly assigned to receive placebo or St. John's wort. Patients not carrying a CYP 2C19 loss-of-function allele (i.e. clopidogrel normal metabolizers) will not require any further follow-up as these patients are considered to display a normal response to clopidogrel. On day 7 following the initiation of the study drug, platelet function testing will be performed. Following a 7 day washout period, patients will be crossed over into the other study group to receive 7 days of study medication. On day 21, the patients will undergo platelet function testing and the study medication will be discontinued.
Conditions
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Study Design
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RANDOMIZED
CROSSOVER
TREATMENT
QUADRUPLE
Study Groups
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AB: Placebo (A); St. Johns Wort (B)
Receive placebo for 7 days, 7 days washout and 7 days of St. Johns Wort
Placebo
Non-active placebo for 7 days: PO/TID
St. Johns Wort
For 7 days: 300mg PO/TID
BA: St. Johns Wort (B); Placebo (A)
Receive St. Johns Wort for 7 days, 7 days washout and 7 days of placebo
Placebo
Non-active placebo for 7 days: PO/TID
St. Johns Wort
For 7 days: 300mg PO/TID
Interventions
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Placebo
Non-active placebo for 7 days: PO/TID
St. Johns Wort
For 7 days: 300mg PO/TID
Eligibility Criteria
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Inclusion Criteria
* Patients with a history of ACS and/or who receive PCI with stent placement at Lancaster General Hospital requiring dual antiplatelet therapy with aspirin and clopidogrel.
Exclusion Criteria
* History of major surgery in the last year (any surgical procedure that involves general anesthesia or respiratory assistance)
* Clinical findings associated with an increased risk of bleeding at the judgment of the investigator
* Patients actively receiving anticoagulation therapy
* Hemoglobin \< 10 g/dL
* Platelets \< 150,000/mm3
* Known hepatic dysfunction
* History of intracranial malignancy or stroke
* Patients receiving thienopyridines chronically prior to PCI
* Concurrent use of CYP P450 2C19 substrates, or inhibiting/ inducing medications with the exception of proton pump inhibitors
* Illicit drug or alcohol abuse
* Daily treatment with nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors
* Allergy to St. Johns wort or lactose
* Patients expected to discontinue dual antiplatelet therapy prior to completion of the study protocol
* Patients unable to adhere to the study protocol
18 Years
ALL
No
Sponsors
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H G Barsumian MD Memorial Fund
OTHER
Louise von Hess Medical Research Institute
OTHER
Lancaster General Hospital
OTHER
Responsible Party
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Michael A. Horst, PhD, MPHS, MS
Director of Research
Principal Investigators
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Kathy M Makkar, PharmD
Role: PRINCIPAL_INVESTIGATOR
Lancaster General Hospital
Roy S Small, MD
Role: PRINCIPAL_INVESTIGATOR
Lancaster General Hospital
Rupal P Dumasia, MD
Role: PRINCIPAL_INVESTIGATOR
Lancaster General Hospital
Jill A Rebuck, PharmD
Role: PRINCIPAL_INVESTIGATOR
Lancaster General Hospital
Michael A Horst, PhD
Role: PRINCIPAL_INVESTIGATOR
Lancaster General Research Institute
Yee M Lee, PharmD
Role: PRINCIPAL_INVESTIGATOR
Lancaster General Hospital
Richard D Paoletti, RPh
Role: PRINCIPAL_INVESTIGATOR
Lancaster General Hospital
Locations
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Lancaster General Hospital
Lancaster, Pennsylvania, United States
Countries
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References
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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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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).
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.
Other Identifiers
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2010-56-LGH
Identifier Type: -
Identifier Source: org_study_id