Drug Interactions and Bioavailability of Cranberry
The purpose of this study is to evaluate the potential of cranberry juice to interact with conventional drugs. This study will also determine the the amount of cranberry flavonoids that appear in the blood and in the urine.
|Study Design:||Allocation: Non-Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Diagnostic
|Official Title:||Drug Interactions and Bioavailability of Cranberry|
|Study Start Date:||October 2004|
|Study Completion Date:||December 2007|
|Primary Completion Date:||December 2007 (Final data collection date for primary outcome measure)|
The use of cranberry (CB) juice and powders, both alone and in combination with conventional medicine, has become more common for the treatment of urinary tract infections (UTIs) and and other acute or chronic conditions. Cytochromes P450 enzymes are a group of proteins involved in metabolism of certain substances. A group of cytochrome P-450 (CYP) enzymes are extensively involved in drug metabolism. The pharmacokinetics of many drugs often vary considerably among individuals, largely because of variations in the expression of different cytochrome P-450 (CYP) enzymes in the liver and other tissues. Flavonoids are antioxidants that may have health benefits. The flavonoids may also be responsible for cranberry's effects on urinary tract infections.
To evaluate the drug interaction potential of cranberry, single doses of the three safe probe drugs alprazolam, dextromethorphan, and caffeine will be administered before and after a 14-day treatment period with cranberry powder. Changes in the pharmacokinetics of these probe drugs will indicate the degree of enzyme inhibition or induction. The key pharmacokinetic parameters for four major CB flavonoids will be estimated by following the plasma concentration versus time course of absorbed flavonoids and their excretion in urine. The area under the plasma concentration versus time curve (AUC), oral clearance (Clo), terminal elimination half-life (T1/2) and renal clearance (Clren) will be determined for: epicatechin, quercetin (total glycosides), procyanidin A2, and cyanidin-3-galactoside.
|United States, South Carolina|
|Medical University of South Carolina|
|Charleston, South Carolina, United States, 29425|
|Principal Investigator:||Jennifer L Donovan, PhD||Medical University of South Carolina|