Trial reportBritish journal of clinical pharmacology2006
Effects of itraconazole and diltiazem on the pharmacokinetics of fexofenadine, a substrate of P-glycoprotein.
Trial report in British journal of clinical pharmacology, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 27 papers.
What it found
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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
27 citing papers in PubMed.
- Ticlopidine inhibits both O-demethylation and renal clearance of tramadol, increasing the exposure to it, but itraconazole has no marked effect on the ticlopidine-tramadol interaction.European journal of clinical pharmacology · 2013Trial
- Influence of Panax ginseng on cytochrome P450 (CYP)3A and P-glycoprotein (P-gp) activity in healthy participants.Journal of clinical pharmacology · 2012Trial
- Effects of oral clotrimazole troches on the pharmacokinetics of oral and intravenous midazolam.British journal of clinical pharmacology · 2010Trial
- Validation and application of a liquid chromatography-tandem mass spectrometric method for quantification of the drug transport probe fexofenadine in human plasma using 96-well filter plates.Journal of chromatography. B, Analytical technologies in the biomedical and life sciences · 2010Trial
- Mechanism of ritonavir changes in methadone pharmacokinetics and pharmacodynamics: II. Ritonavir effects on CYP3A and P-glycoprotein activities.Clinical pharmacology and therapeutics · 2008Trial
- The different effects of itraconazole on the pharmacokinetics of fexofenadine enantiomers.British journal of clinical pharmacology · 2008Trial
- Effects of single and multiple doses of itraconazole on the pharmacokinetics of fexofenadine, a substrate of P-glycoprotein.British journal of clinical pharmacology · 2006Trial
- Potential Links Between Aging, Mitochondrial Dysfunction, and Drug Transporter Function-Molecular Mechanisms and Pharmacokinetic Implications.International journal of molecular sciences · 2026Review
- A Mechanistic Physiologically Based Pharmacokinetic (PBPK) modeling approach for fexofenadine: predictive pharmacokinetic insights in humans.Saudi pharmaceutical journal : SPJ : the official publication of the Saudi Pharmaceutical Society · 2025Article
- Clinical Pharmacokinetics of Fexofenadine: A Systematic Review.Pharmaceutics · 2024Review
- Deconvoluting zavegepant drug-drug interactions: A phase I study to evaluate the effects of rifampin and itraconazole on zavegepant pharmacokinetics.Clinical and translational science · 2024Article
- Critical Assessment of Phenotyping Cocktails for Clinical Use in an African Context.Journal of personalized medicine · 2023Review
- Prediction of the drug-drug interaction potential of the α1-acid glycoprotein bound, CYP3A4/CYP2C9 metabolized oncology drug, erdafitinib.CPT: pharmacometrics & systems pharmacology · 2021Article
- Improved Dissolution Rate and Intestinal Absorption of Fexofenadine Hydrochloride by the Preparation of Solid Dispersions: In Vitro and In Situ Evaluation.Pharmaceutics · 2021Article
- Interaction between Fexofenadine and CYP Phenotyping Probe Drugs in Geneva Cocktail.Journal of personalized medicine · 2019Article
- Renal Drug Transporters and Drug Interactions.Clinical pharmacokinetics · 2017Review
- Review
- The influence of piperine on the pharmacokinetics of fexofenadine, a P-glycoprotein substrate, in healthy volunteers.European journal of clinical pharmacology · 2017Article
- Psychotropic drug-drug interactions involving P-glycoprotein.CNS drugs · 2012Review
- In vitro-in situ permeability and dissolution of fexofenadine with kinetic modeling in the presence of sodium dodecyl sulfate.European journal of drug metabolism and pharmacokinetics · 2012Article
Corrections and comments
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Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
aimsFexofenadine is a substrate of several drug transporters including P-glycoprotein. Our objective was to evaluate the possible effects of two P-glycoprotein inhibitors, itraconazole and diltiazem, on the pharmacokinetics of fexofenadine, a putative probe of P-glycoprotein activity in vivo, and compare the inhibitory effect between the two in healthy volunteers.
methodsIn a randomized three-phase crossover study, eight healthy volunteers were given oral doses of 100 mg itraconazole twice daily, 100 mg diltiazem twice daily or a placebo capsule twice daily (control) for 5 days. On the morning of day 5 each subject was given 120 mg fexofenadine, and plasma concentrations and urinary excretion of fexofenadine were measured up to 48 h after dosing.
resultsItraconazole pretreatment significantly increased mean (+/-SD) peak plasma concentration (Cmax) of fexofenadine from 699 (+/-366) ng ml-1 to 1346 (+/-561) ng ml-1 (95% CI of differences 253, 1040; P<0.005) and the area under the plasma concentration-time curve [AUC0,infinity] from 4133 (+/-1776) ng ml-1 h to 11287 (+/-4552) ng ml-1 h (95% CI 3731, 10575; P<0.0001). Elimination half-life and renal clearance in the itraconazole phase were not altered significantly compared with those in the control phase. In contrast, diltiazem pretreatment did not affect Cmax (704+/-316 ng ml-1, 95% CI -145, 155), AUC0, infinity (4433+/-1565 ng ml-1 h, 95% CI -1353, 754), or other pharmacokinetic parameters of fexofenadine.
conclusionsAlthough some drug transporters other than P-glycoprotein are thought to play an important role in fexofenadine pharmacokinetics, itraconazole pretreatment increased fexofenadine exposure, probably due to the reduced first-pass effect by inhibiting the P-glycoprotein activity. As diltiazem pretreatment did not alter fexofenadine pharmacokinetics, therapeutic doses of diltiazem are unlikely to affect the P-glycoprotein activity in vivo.
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