The Impact of Grapefruit Juice on the Response to Clopidogrel

August 28, 2012 updated by: Creighton University

The Impact of Grapefruit Juice on the Response to a Loading Dose and Maintenance Dose of Clopidogrel in Healthy Volunteers

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment (Actual)

32

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Nebraska
      • Omaha, Nebraska, United States, 68131
        • Creighton Cardiac Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

15 years to 36 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Screening
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
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

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
% Platelet Inhibition
Time Frame: 6 hours
% platelet inhibition measured by Verify Now
6 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Creighton University

Investigators

  • Principal Investigator: Tammy Burns, PharmD, Creighton Cardiac Center

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2008

Primary Completion (Actual)

July 1, 2011

Study Completion (Actual)

July 1, 2011

Study Registration Dates

First Submitted

January 6, 2009

First Submitted That Met QC Criteria

January 6, 2009

First Posted (Estimate)

January 7, 2009

Study Record Updates

Last Update Posted (Estimate)

October 1, 2012

Last Update Submitted That Met QC Criteria

August 28, 2012

Last Verified

August 1, 2012

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 08-15073

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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