Do Furanocoumarins Mediate the Fexofenadine-grapefruit Juice Interaction?
Information source: University of North Carolina, Chapel Hill
ClinicalTrials.gov processed this data on August 23, 2015 Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Food-drug Interaction
Intervention: Fexofenadine (Drug)
Phase: N/A
Status: Completed
Sponsored by: University of North Carolina, Chapel Hill Official(s) and/or principal investigator(s): Mary F Paine, PhD, Principal Investigator, Affiliation: UNC-Chapel Hill
Summary
Purpose: Grapefruit juice is one of the most extensively studied dietary/natural substances
shown to interact with a variety of medications. However, unanswered questions remain
regarding the causative ingredients and mechanisms underlying such drug-grapefruit juice
interactions. Compounds in grapefruit juice called furanocoumarins have been established as
major causative ingredients, which act by inhibiting the elimination (metabolism) of drugs,
leading to increased circulating drug concentrations. Increased drug concentrations can in
turn lead to increased drug potency or even toxicity. Grapefruit juice also has been shown,
paradoxically, to decrease circulating concentrations of some drugs, including the
non-sedating antihistamine agent, fexofenadine (Allegra), which undergoes negligible
metabolism. Whether or not furanocoumarins mediate the decrease in fexofenadine
concentrations is unknown. The purpose of the proposed study is to compare the effects of a
"furanocoumarin-free" grapefruit juice with grapefruit juice on circulating concentrations
of fexofenadine.
Clinical Details
Official title: Do Furanocoumarins Mediate the Fexofenadine-grapefruit Juice Interaction?
Study design: Allocation: Randomized, Endpoint Classification: Pharmacokinetics Study, Intervention Model: Crossover Assignment, Masking: Open Label
Primary outcome: Primary Pharmacokinetic Measure: Area Under the Curve (AUC)
Detailed description:
Participants: Healthy volunteers of any race/ethnicity, ranging in age from 18 to 65 years,
will be enrolled.
Procedures (methods): Procedures will include administration of water, furanocoumarin-free
grapefruit juice, or grapefruit juice with fexofenadine; placement of an intravenous (IV)
line; and collection of blood over 72 hours.
Eligibility
Minimum age: 18 Years.
Maximum age: 65 Years.
Gender(s): Both.
Criteria:
Inclusion Criteria:
- Men or women between the ages of 18 and 65
- Normal screening laboratory test results
- Able to understand the informed consent form
- Willing to abstain from grapefruit products and all fruit juices for one week prior
to and during the study
- Willing to abstain from alcohol and caffeinated beverages the evening prior to each
study day
Exclusion Criteria:
- History of intolerance to grapefruit products
- History of any allergy or hypersensitivity to grapefruit products or fexofenadine
- History of significant medical conditions that the study physician believes would
increase risk
- History of significant alcohol abuse and/or illicit drug use
- Tobacco use within the month preceding the study
- Pregnancy or breast-feeding
- Taking concomitant medications, both prescription and non-prescription (including
herbal products), known to alter fexofenadine blood levels or P-gp and/or OATP
activity (women stabilized on hormonal methods of birth control will be allowed to
participate)
Locations and Contacts
North Carolina Clinical and Translational Research Center, Chapel Hill, North Carolina 27599, United States
Additional Information
Starting date: September 2009
Last updated: December 29, 2012
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