ArticleBritish journal of clinical pharmacology2009
4beta-hydroxycholesterol as an endogenous marker for CYP3A4/5 activity. Stability and half-life of elimination after induction with rifampicin.
Article in British 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 63 papers.
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Who cites it
63 citing papers in PubMed, 122 citations in OpenAlex.
- Serum 4β-hydroxycholesterol increases during fluconazole treatment.European journal of clinical pharmacology · 2021Trial
- Pharmacokinetics, pharmacodynamics and safety of the inverse retinoic acid-related orphan receptor γ agonist AZD0284.British journal of clinical pharmacology · 2020Trial
- Identification of the caffeine to trimethyluric acid ratio as a dietary biomarker to characterise variability in cytochrome P450 3A activity.European journal of clinical pharmacology · 2019Trial
- Erlotinib treatment induces cytochrome P450 3A activity in non-small cell lung cancer patients.British journal of clinical pharmacology · 2019Trial
- Inflammation down-regulates CYP3A4-catalysed drug metabolism in hemodialysis patients.BMC pharmacology & toxicology · 2018Trial
- The CYP3A biomarker 4β-hydroxycholesterol does not improve tacrolimus dose predictions early after kidney transplantation.British journal of clinical pharmacology · 2017Trial
- 4β-hydroxycholesterol as an endogenous CYP3A marker in cancer patients treated with taxanes.British journal of clinical pharmacology · 2015Trial
- Validation of 4β-hydroxycholesterol and evaluation of other endogenous biomarkers for the assessment of CYP3A activity in healthy subjects.British journal of clinical pharmacology · 2014Trial
- Comparison of two endogenous biomarkers of CYP3A4 activity in a drug-drug interaction study between midostaurin and rifampicin.European journal of clinical pharmacology · 2014Trial
- Unbound Intrinsic Formation Clearance of 6β-Hydroxycortisol Is a Useful Biomarker of CYP3A4 Activity during Pregnancy.Clinical pharmacology and therapeutics · 2026Article
- Untargeted Metabolomics Reveal New Endogenous Plasma Biomarkers Associated with CYP3A Inhibition in Humans.Clinical pharmacology and therapeutics · 2026Article
- Endogenous biomarkers for assessing CYP3A4 and CYP2D6 activity: A critical review.Drug metabolism and disposition: the biological fate of chemicals · 2026Review
- Predicting Pharmacokinetic Variability and Drug Interaction Risk Using Omics-Based Biomarkers.Clinical and translational science · 2026Review
- Impact of Efavirenz on Heme Protein Induction and Biomarkers: Insights From In Vitro Experiments and a Clinical Study.Clinical and translational science · 2026Article
- Dynamic phenotype monitoring to prevent genotype-phenotype discrepancies in pharmacogenetic-guided drug therapy.Frontiers in pharmacology · 2026Review
- The effect of carbamazepine, a strong CYP3A inducer, on the pharmacokinetics of zongertinib in healthy male volunteers.Pharmacotherapy · 2025Article
- Interindividual variability in CYP3A-mediated venetoclax metabolism in vitro and in vivo in patients with chronic lymphocytic leukemia.Clinical and translational science · 2024Article
- Roles of Individual Human Cytochrome P450 Enzymes in Drug Metabolism.Pharmacological reviews · 2024Review
- Relevance of plasma lenvatinib concentrations and endogenous urinary cytochrome P450 3A activity biomarkers in clinical practice.Pharmacology research & perspectives · 2024Article
- Induction of hepatic CYP3A4 expression by cholesterol and cholic acid: Alterations of gene expression, microsomal activity, and pharmacokinetics.Pharmacology research & perspectives · 2024Article
3 more citing papers are in PubMed but not listed here.
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Authors and funding
6 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
aimsThe oxysterol 4beta-hydroxycholesterol has been suggested as a marker for CYP3A4/5 activity. We have previously shown that plasma 4beta-hydroxycholesterol continues to increase for several weeks after maximal induction of CYP3A4/5 by carbamazepine at the dose given. In the present study we aimed to determine the time course of the decrease in plasma 4beta-hydroxycholesterol after termination of induction of CYP3A4/5 by rifampicin. An additional aim was to determine the variation in plasma level of 4beta-hydroxycholesterol with time in 12 untreated healthy volunteers.
methodsTwenty-four healthy subjects were allocated into three study groups of equal sizes. The volunteers were treated with rifampicin (either 20 mg day(-1), 100 mg day(-1) or 500 mg day(-1)) for 2 weeks. Blood samples were taken before, during and after rifampicin treatment. In another group of 12 untreated volunteers blood samples were collected at different time points in order to determine the intraindividual variations in plasma 4beta-hydroxycholesterol concentrations. Plasma levels of 4beta-hydroxycholesterol were determined by isotope-dilution gas chromatography-mass spectrometry.
resultsRifampicin treatment increased plasma 4beta-hydroxycholesterol levels. After termination of rifampicin treatment plasma levels of 4beta-hydroxycholesterol decreased slowly with an apparent half-life of 17 days. The intraindividual variation in plasma levels of 4beta-hydroxycholesterol in untreated subjects was low, with coefficients of variation of between 4.8 and 13.2% over a period of 3 months.
conclusionsAfter termination of induction of CYP3A4/5, plasma 4beta-hydroxycholesterol levels decreased slowly during 8 weeks. The half-life of elimination (17 days) resembled that of cholesterol rather than other oxysterols. The long half-life results in stable plasma concentrations with time.
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