Fluoxetine (FLX) is one of the most widely prescribed selective serotonin reuptake inhibitors. Although FLX is used as racemate in the clinic, the clinical pharmacokinetics of FLX and its N-demethylation metabolite norfluoxetine (NFLX) show obvious cytochrome P450 (CYP) polymorphism dependency and exhibit marked stereoselectivity. However, the kinetic profiles of CYP variants to FLX remain unclear. In the present study, some variants of human CYP2C8, CYP2C9, and CYP2D6 were first expressed in insect cells, and their catalytic roles with respect to FLX enantiomers were then investigated. CYP2C8.4 and CYP2C9.10 showed significantly lower activity and CYP2C8.3 showed significantly higher activity toward both R- and S-FLX compared with the wildtype, while CYP2C9.3, CYP2C9.13, and CYP2C9.16 showed significantly lower activity only toward R-FLX. Five CYP2C9 variants and CYP2D6.1 exhibited significantly stereoselective kinetic profiles prior to R-FLX, and CYP2C8.3 showed a slight stereoselectivity. Interestingly, obvious substrate inhibition was observed in the CYP2C9 wildtype and its three variants only in the case of R-FLX. Together, these findings suggest that CYP2C9 and CYP2D6 polymorphism may play an important role in the clearance of FLX and also in the stereoselective kinetic profiles of FLX enantiomers.
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http://dx.doi.org/10.1002/chir.22289 | DOI Listing |
J Mol Diagn
January 2025
Clinical Research and Technological Development Division (Divisão de Pesquisa Clínica e Desenvolvimento Tecnológico), Brazilian National Cancer Institute (Instituto Nacional de Câncer), Rio de Janeiro, Brazil. Electronic address:
This article examines the frequency distribution of Tier 1 pharmacogenetic variants of the Association for Molecular Pathology Pharmacogenomics Working Group Recommendations in two large (>1.000 individuals) cohorts of the admixed Brazilian population, and in patients from the Brazilian Public Health System enrolled in pharmacogenetic trials. Three Tier 1 variants, all in DPYD, were consistently absent, which may justify their non-inclusion in genotyping panels for Brazilians; 13 variants had frequency < 1.
View Article and Find Full Text PDFFront Pharmacol
January 2025
State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy and Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China.
Introduction: Deglycosylated azithromycin (Deg-AZM), a new transgelin agonist with positive therapeutic effects on slow transit constipation, has been approved for clinical trials in 2024. This work investigated the drug metabolism and transport of Deg-AZM to provide research data for further development of Deg-AZM.
Methods: A combination of UPLC-QTOF-MS was used to obtain metabolite spectra of Deg-AZM in plasma, urine, feces and bile.
Sci Rep
January 2025
Institute for Breath Research, University of Innsbruck, Innrain 80/82, Innsbruck, 6020, Austria.
Cytochrome P450 (CYP) 3A4 plays a major role in drug metabolism. Its activity could be determined by non-invasive and cost-effective assays, such as breath analysis, for the personalised monitoring of drug response. For the first time, we identify an isotopically unlabelled CYP3A4 substrate, tolterodine that leads to the formation of a non-toxic volatile metabolite, acetone, which could potentially be applied to monitor CYP3A4 activity in humans.
View Article and Find Full Text PDFSLAS Discov
January 2025
iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12 2781-901 Oeiras, Portugal; ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier, Av. Republica, 2780-157, Oeiras, Portugal. Electronic address:
Primary human hepatocytes (PHHs) are the preferred cell source to address liver function. Despite originating from the native tissue, one of the bottlenecks when using primary material is the donor-to-donor variability. Cryopreserved PHHs offer a high number of cells from the same donor and standardization of cell isolation and cryopreservation procedures, mitigating some of the inter-donor variability.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Institute of Biomedical Chemistry, Pogodinskaya Street, 10, Build 8, 119121 Moscow, Russia.
This study aimed to investigate whether the water-soluble pharmaceutical form of phosphatidylcholine nanoparticles (wPC) stimulated the catalytic activity of CYP enzymes 2C9 and 2D6. We have shown that electroenzymatic CYP2C9 catalysis to nonsteroidal anti-inflammatory drug naproxen as a substrate was enhanced from 100% to 155% in the presence of wPC in media. Electroenzymatic CYP2D6 activity in the presence of the adrenoceptor-blocking agent bisoprolol as a substrate was elevated significantly from 100% to 144% when wPC was added to potassium phosphate buffer solution.
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