Trial reportBritish journal of clinical pharmacology1999
Ticlopidine decreases the in vivo activity of CYP2C19 as measured by omeprazole metabolism.
Trial report in British journal of clinical pharmacology, 1999. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 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.
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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
11 citing papers in PubMed, 44 citations in OpenAlex.
- PBPK Analysis to Study the Impact of Genetic Polymorphism of NAT2 on Drug-Drug Interaction Potential of Isoniazid.Pharmaceutical research · 2021Article
- Interactions of 7,8-Dihydroxyflavone with Serum Albumin as well as with CYP2C9, CYP2C19, CYP3A4, and Xanthine Oxidase Biotransformation Enzymes.Biomolecules · 2019Article
- In vivo quantitative prediction of the effect of gene polymorphisms and drug interactions on drug exposure for CYP2C19 substrates.The AAPS journal · 2013Article
- Clinical Application of CYP2C19 Pharmacogenetics Toward More Personalized Medicine.Frontiers in genetics · 2012Article
- Structures of cytochrome P450 2B4 complexed with the antiplatelet drugs ticlopidine and clopidogrel .Biochemistry · 2010Article
- Ticlopidine-induced hepatotoxicity is associated with specific human leukocyte antigen genomic subtypes in Japanese patients: a preliminary case-control study.The pharmacogenomics journal · 2008Article
- Interspecies pharmacokinetics and in vitro metabolism of SQ109.British journal of pharmacology · 2006Article
- Clinical significance of the cytochrome P450 2C19 genetic polymorphism.Clinical pharmacokinetics · 2002Review
- Inhibition of cytochrome P450 (CYP450) isoforms by isoniazid: potent inhibition of CYP2C19 and CYP3A.Antimicrobial agents and chemotherapy · 2001Article
- In vitro inhibition of the cytochrome P450 (CYP450) system by the antiplatelet drug ticlopidine: potent effect on CYP2C19 and CYP2D6.British journal of clinical pharmacology · 2000Article
- Analysis of antiplatelet effect of ticlopidine in humans: modeling based on irreversible inhibition of platelet precursors in bone marrow.Journal of pharmacokinetics and biopharmaceutics · 1999Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
aimsTo examine the effect of ticlopidine administration on the activities CYP2C19 and CYP3 A in vivo using omeprazole as a model substrate.
methodsA single dose of 40 mg omeprazole was administered orally with or without ticlopidine (300 mg daily for 6 days) to six Japanese extensive metabolisers with respect to CYP2C19. Blood samples were taken for the measurement of plasma concentrations of omeprazole, 5-hydroxyomeprazole and omeprazole sulphone.
resultsTiclopidine administration increased omeprazole Cmax (1978+/-859/ 3442+/-569 (control phase/ticlopidine phase, nm )) and decreased the oral clearance of omeprazole (CL/F; 25.70+/-16. 17/10.76+/-1.16 (control phase/ticlopidine phase, l h-1 )) significantly. The 5-hydroxyomeprazole to omeprazole AUC ratio (0. 817+/-0.448/0.236+/-0.053 (control phase/ticlopidine phase)) and the 5-hydroxyomeprazole to omeprazole sulphone AUC ratio (1.114+/-0. 782/0.256+/-0.051 (control phase/ticlopidine phase)) were decreased significantly after ticlopidine administration. The decrease in omeprazole CL/F and the 5-hydroxyomeprazole to omeprazole AUC ratio correlated significantly with their respective absolute values when the drug was given alone. The decrease in CL/F following ticlopidine administration correlated with that in the 5-hydroxyomeprazole to omeprazole AUC ratio.
conclusionsThese findings suggest that ticlopidine inhibited the in vivo activity of CYP2C19, but not, or to a lesser extent CYP3 A4, and that the magnitude of inhibition by ticlopidine is related to the in vivo activity of CYP2C19 before inhibition.
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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.