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The Impact of Grapefruit Juice on the Response to Clopidogrel

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00817999
First Posted: January 7, 2009
Last Update Posted: October 1, 2012
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
Creighton University
  Purpose
This study will measure the percentage of platelet aggregation inhibition with a loading dose of clopidogrel (300 mg) using the VerifyNow Assay System in healthy volunteers who have drank 11 oz of grapefruit juice. It will also measure the percentage of platelet aggregation inhibition with a maintenance dose of clopidogrel (75 mg/day) using the VerifyNow Assay System in healthy volunteers who have drank 11 oz grapefruit juice daily.

Condition Intervention Phase
Healthy Dietary Supplement: Grapefruit juice Drug: Clopidogrel 75 mg/day Drug: Clopidogrel 300 mg Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Screening
Official Title: The Impact of Grapefruit Juice on the Response to a Loading Dose and Maintenance Dose of Clopidogrel in Healthy Volunteers

Resource links provided by NLM:


Further study details as provided by Creighton University:

Primary Outcome Measures:
  • % Platelet Inhibition [ Time Frame: 6 hours ]
    % platelet inhibition measured by Verify Now


Enrollment: 32
Study Start Date: November 2008
Study Completion Date: July 2011
Primary Completion Date: July 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Loading Dose
Participants received a 300 mg dose of clopidogrel with or without GFJ.
Dietary Supplement: Grapefruit juice
Participants received grapefruit juice during 1 of the 2 periods.
Drug: Clopidogrel 300 mg
Experimental: Maintenance Dose
Participants received clopidogrel 75 mg/day for 7 days with or without GFJ
Dietary Supplement: Grapefruit juice
Participants received grapefruit juice during 1 of the 2 periods.
Drug: Clopidogrel 75 mg/day

Detailed Description:

This study will examine the effect of GFJ on the loading dose (300 mg) of clopidogrel and will evaluate the effect of GFJ on the maintenance dose (75 mg/day) of clopidogrel. Subjects will be randomized to either initially receive GFJ prior to their loading dose of clopidogrel or receive GFJ prior to their second loading dose. The subjects who have been randomized to receive GFJ initially will drink two small cans (11 oz total) of regular strength GFJ in the morning, followed two hours later by a loading dose (300 mg) of clopidogrel and will then return to the clinic 6 hours after their loading dose to have their platelet inhibition measured. Subjects will have ~ 5 milliliters (1 teaspoonful) of whole blood drawn from an antecubital vein in their forearm via a 21 gauge needle attached to a blue-top plastic vacuette sodium citrate blood collection (Greiner, Monroe, NC) tube to test inhibition of platelet aggregation. After their first loading dose, a 2 week washout period will follow to allow for their platelet aggregation to return to normal. Following the washout period, the subjects will take their second loading dose of clopidogrel and again return to the clinic for platelet inhibition measurement. The same timing will be followed for the loading dose taken without prior GFJ.

During the maintenance dose phase of this study, subjects will take 75 mg/day clopidogrel for 7 days with or without GFJ. Subjects will be randomized to either GFJ during the first period or GFJ during the second period. A minimum 2 week washout period will occur between the two 7 day courses of clopidogrel. Platelet inhibition measurement will occur at the end of each 7 day period as described above.

  Eligibility

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Ages Eligible for Study:   19 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Ages 19-40
  • Health status confirmed by medical history and physical examination and laboratory analysis

Exclusion Criteria:

  • Pregnancy
  • Taking routine prescription or over-the-counter prescriptions
  • Taken over-the-counter analgesic/anti-inflammatory medication within two weeks of study participation
  • Recently had grapefruit juice or regularly drinks grapefruit juice
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00817999


Locations
United States, Nebraska
Creighton Cardiac Center
Omaha, Nebraska, United States, 68131
Sponsors and Collaborators
Creighton University
Investigators
Principal Investigator: Tammy Burns, PharmD Creighton Cardiac Center
  More Information

Responsible Party: Creighton University
ClinicalTrials.gov Identifier: NCT00817999     History of Changes
Other Study ID Numbers: 08-15073
First Submitted: January 6, 2009
First Posted: January 7, 2009
Results First Submitted: August 8, 2011
Results First Posted: October 1, 2012
Last Update Posted: October 1, 2012
Last Verified: August 2012

Keywords provided by Creighton University:
Platelet Aggregation Inhibition

Additional relevant MeSH terms:
Clopidogrel
Ticlopidine
Platelet Aggregation Inhibitors
Purinergic P2Y Receptor Antagonists
Purinergic P2 Receptor Antagonists
Purinergic Antagonists
Purinergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Fibrinolytic Agents
Fibrin Modulating Agents
Cytochrome P-450 CYP2C19 Inhibitors
Cytochrome P-450 Enzyme Inhibitors
Enzyme Inhibitors