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Effects of Garlic Supplements on Drug Metabolism

This study has been completed.
Sponsor:
Collaborator:
National Center for Complementary and Alternative Medicine (NCCAM)
Information provided by:
Fred Hutchinson Cancer Research Center
ClinicalTrials.gov Identifier:
NCT00122889
First received: July 20, 2005
Last updated: December 30, 2009
Last verified: December 2009
History of Changes

July 20, 2005
December 30, 2009
July 2005
Not Provided
Blood plasma and urine samples [ Time Frame: 3 months ] [ Designated as safety issue: No ]
Not Provided
Complete list of historical versions of study NCT00122889 on ClinicalTrials.gov Archive Site
Blood plasma and breath samples. [ Time Frame: 3 months ] [ Designated as safety issue: No ]
Not Provided
Not Provided
Not Provided
 
Effects of Garlic Supplements on Drug Metabolism
Garlic Metabolism and Cytochrome P450 Modulation

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

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.
Observational
Observational Model: Case-Only
Time Perspective: Prospective
Not Provided
Retention:   Samples With DNA
Description:

Whole blood, urine
Non-Probability Sample

Healthy volunteers
Healthy
  • Drug: Garlic powder with high allicin content
  • Drug: Garlic powder with low allicin content
  • Drug: Garlic oil
  • Drug: Aged garlic
Not Provided
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
80
March 2009
Not Provided

Inclusion Criteria:

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

Exclusion Criteria:

  • 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
Both
18 Years to 45 Years
Yes
Contact information is only displayed when the study is recruiting subjects
United States
 
NCT00122889
FHCRC-1984.00, R21 AT002712-01
No
Danny Shen, PhD, Fred Hutchinson Cancer Research Center
Fred Hutchinson Cancer Research Center
National Center for Complementary and Alternative Medicine (NCCAM)
Principal Investigator: Danny D. Shen, PhD Fred Hutchinson Cancer Research Center
Fred Hutchinson Cancer Research Center
December 2009

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP