Trial reportEuropean journal of clinical pharmacology2009
Short-term effect of quercetin on the pharmacokinetics of fexofenadine, a substrate of P-glycoprotein, in healthy volunteers.
Trial report in European journal of clinical pharmacology, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 28 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
28 citing papers in PubMed, 1 synthesis or guideline pooled it, 84 citations in OpenAlex.
- Quercetin as a modulator of xenobiotic metabolism: integrating CYP450 regulation, phase II conjugation pathways, and transporter-mediated drug interactions.European journal of clinical pharmacology · 2026Pooled it
- Role of (-)-epigallocatechin gallate in the pharmacokinetic interaction between nadolol and green tea in healthy volunteers.European journal of clinical pharmacology · 2018Trial
- The Pharmacokinetic Exposure to Fexofenadine is Volume-Dependently Reduced in Healthy Subjects Following Oral Administration With Apple Juice.Clinical and translational science · 2016Trial
- The role of P-glycoprotein in CNS antihistamine effects.Psychopharmacology · 2013Trial
- Effect of quercetin on P-glycoprotein transport ability in Chinese healthy subjects.European journal of clinical nutrition · 2013Trial
- Effect of metronidazole on the pharmacokinetics of fexofenadine, a P-glycoprotein substrate, in healthy male volunteers.European journal of clinical pharmacology · 2010Trial
- Quercetin and Its Nano-Based Formulations Against Skin Cancer: A Narrative Review.Health science reports · 2026Article
- Pharmacokinetic Prediction and Cytotoxicity of New Quercetin Derivatives.Chemistry & biodiversity · 2025Article
- Clinical Pharmacokinetics of Fexofenadine: A Systematic Review.Pharmaceutics · 2024Review
- Enhanced Chemoprevention of Prostate Cancer by Combining Arctigenin with Green Tea and Quercetin in Prostate-Specific Phosphatase and Tensin Homolog Knockout Mice.Biomolecules · 2024Article
- Article
- Phenotyping Indices of CYP450 and P-Glycoprotein in Human Volunteers and in Patients Treated with Painkillers or Psychotropic Drugs.Pharmaceutics · 2023Article
- Redesigning Nature: Ruthenium Flavonoid Complexes with Antitumour, Antimicrobial and Cardioprotective Activities.Molecules (Basel, Switzerland) · 2021Review
- Article
- Effect of P-glycoprotein (P-gp) Inducers on Exposure of P-gp Substrates: Review of Clinical Drug-Drug Interaction Studies.Clinical pharmacokinetics · 2020Review
- Interaction between Fexofenadine and CYP Phenotyping Probe Drugs in Geneva Cocktail.Journal of personalized medicine · 2019Article
- Drug Bioavailability Enhancing Agents of Natural Origin (Bioenhancers) that Modulate Drug Membrane Permeation and Pre-Systemic Metabolism.Pharmaceutics · 2019Review
- Phytotherapeutics: The Emerging Role of Intestinal and Hepatocellular Transporters in Drug Interactions with Botanical Supplements.Molecules (Basel, Switzerland) · 2017Review
- The influence of piperine on the pharmacokinetics of fexofenadine, a P-glycoprotein substrate, in healthy volunteers.European journal of clinical pharmacology · 2017Article
- Molecular mechanisms of action of quercetin in cancer: recent advances.Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine · 2016Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectiveThe aim of the present study was to assess whether quercetin exhibited any inhibitory effect on P-glycoprotein (P-gp)-mediated drug disposition in humans using fexofenadine as a P-gp substrate.
methodsTwelve healthy subjects were enrolled in the study and treated daily for 7 days with 500 mg quercetin or placebo 3 times a day. On day 7, a single dose of 60 mg fexofenadine was administered orally. Plasma and urinary fexofenadine concentrations were measured, and pharmacokinetic differences between placebo and quercetin phases were assessed.
resultsThe mean plasma concentrations of fexofenadine were significantly increased after quercetin treatment compared to those of the placebo phase. The area under the time versus concentration curve (AUC) of plasma fexofenadine was increased by 55% by quercetin (2,005.3 versus 3,098.6 ng.h/mL, P < 0.001) and similarly the maximum plasma concentration (C(max)) during the quercetin phase was elevated by 68% compared to that of the placebo phase (295.3 versus 480.3 ng/mL, P = 0.006). Although the oral clearance of fexofenadine was decreased significantly by 37% after quercetin treatment (61.4 versus 38.7 L/h, P < 0.001), no differences in the renal clearance and half-life were observed between placebo and quercetin phases.
conclusionThe results of the present study showed that short-term use of quercetin elevated the plasma concentrations of fexofenadine, probably by the inhibition of P-gp-mediated efflux in humans.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.