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HealthyNCT00122889

Effects of Garlic Supplements on Drug Metabolism

An observational study of Healthy, run by Fred Hutchinson Cancer Center at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study will determine whether garlic supplements affect the way certain drugs are processed in the body. Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
Conditions the study is for
Healthy
What is being tested?
Garlic powder with high allicin content, Garlic powder with low allicin content and Garlic oil
How many people
80 participants
Where
1 siteUnited States
Study dates
Jul 2005to Mar 2009
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Study population: Healthy volunteers

Who may be able to join

  • Body mass index (BMI) between 20 and 32
  • Able to read and understand English
  • MUST LIVE WITHIN THE SEATTLE, WA AREA.

Who cannot join

  • Current use of herbal medicines other than oral contraceptives
  • History of cardiopulmonary, liver, renal or endocrine disease
  • Allergy or sensitivity to any of the drugs that will be used in the probe cocktails or the garlic supplements
  • Daily consumption of vegetables with a high allium content, including garlic, shallots, leeks, and chives
  • Pregnancy or breastfeeding

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Fred Hutchinson Cancer Research Center

    Seattle, Washington, 98109

Other trials in United States

About this study

Official title: Garlic Metabolism and Cytochrome P450 Modulation

This study will determine whether garlic supplements affect the way certain drugs are processed in the body.

Read the detailed description

Garlic supplements, which are often used to lower cholesterol and prevent cancer, are one of the most commonly used herbal products in the United States.

However, little is known about the way garlic supplements may interact with prescription medications when used simultaneously. This study will investigate four commonly used garlic supplements: garlic powder with a low content of allicin (a compound with antibacterial properties), garlic powder with a high allicin content, garlic oil, and aged garlic. The effects of these 4 garlic products on the drug-metabolizing enzyme cytochrome P450 (CYP) and a drug transporter, P-glycoprotein (Pgp) will be examined.

Participants will be randomly assigned to receive one of the four garlic supplements for 4 weeks. Drug probes of CYP and Pgp will be used to assess the in vivo activities of the substances. On the first day of garlic ingestion, blood collection will occur immediately after participants ingest their garlic supplement and 3, 4, and 6 hours after ingestion. Urine collection will occur immediately after participants' first garlic ingestion and 12, 15, and 72 hours after ingestion. Blood and urine collection will determine the concentration of the drug probes in the body, which will indicate changes in CYP and Pgp. Blood and urine tests will be repeated at the end of the study.

Conditions
Healthy
Being tested
Garlic powder with high allicin content, Garlic powder with low allicin content, Garlic oil, Aged garlic
Keywords
Drug Interactions, Pharmacokinetics, Garlic, Complementary Therapies, Complementary and Alternative Medicine

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Garlic powder with high allicin contentDrug

  • Garlic powder with low allicin contentDrug

  • Garlic oilDrug

  • Aged garlicDrug

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Blood plasma and urine samples

    Measured: 3 months

Secondary outcomes (1)
  1. Blood plasma and breath samples.

    Measured: 3 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Jul 2005 (estimated)
  2. Study startJul 2005
  3. Study completionMar 2009

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case only
Time perspective
Prospective
Enrolment
80 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00122889
Sponsor's protocol ID
FHCRC-1984.00
Other IDs
R21AT002712-01
Status last verified
Dec 2009
First submitted
20 Jul 2005
Last updated
1 Jan 2010
Results posted
No
Data monitoring committee
No

Questions about this trial

What is this clinical trial studying?

An observational study of Healthy, run by Fred Hutchinson Cancer Center at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 1 Jan 2010. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Blood plasma and urine samples (time frame: 3 months). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Jan 2010.

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