An optimized methodology for combined phenotyping and genotyping on CYP2D6 and CYP2C19

Tamminga, Wim J.; Wemer, J.; Oosterhuis, B.; Brakenhoff, J. P. G.; Gerrits, Mireille; Zeeuw, Rokus A. de; Leij, Lou F. M. H. de; Jonkman, J. H. G.

doi:10.1007/s002280100273

Cited by 34 publications

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“…However, by further adapting the AS system for use of omeprazole as a probe drug (Table 1), a significant improvement in predictive power was 18 demonstrated (Figure 4). This modification was particularly relevant for the well-studied, increased metabolism CYP2C19*17 allele [31,32], which contrary to expectations was observed to have no influence on OME metabolism in this cohort. This may suggest that OME might not be sensitive enough as a probe drug for CYP2C19 metabolism.…”

Section: Cyp2c19 Comparison Between Predicted and Measured Phenotypecontrasting

confidence: 87%

“…By correlating two, three and four hour data intervals, it was determined that a three hour sampling would be the most reliable and convenient time point to use in future investigations. The three hour time point has previously been used to phenotype CYP2C19 using OME and 5OH concentrations in plasma [31,32]. Sampling should be performed after the T max , so as to avoid increasing plasma levels of the drug interfering with measurements.…”

Section: Phenotypingmentioning

confidence: 99%

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Evaluation of Predictive Cyp2C19 Genotyping Assays Relative to Measured Phenotype in a South African Cohort

et al. 2015

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Aim: To align predicted and measured CYP2C19 phenotype in a South African cohort. Materials and methods:Genotyping of CYP2C19*2, *3, *9, *15, *17, *27 and *28 was performed using PCR-RFLP, and an Activity Score (AS) system was used to predict phenotype. 2True phenotype was measured using plasma concentrations of omeprazole and its metabolite 5'-hydroxyomperazole. Results: Partial genotype-phenotype discrepancies were reported, and an adapted AS system was developed, which showed a marked improvement in phenotype prediction. Results highlight the need for a more comprehensive CYP2C19 genotyping approach to improve prediction of omeprazole metabolism. Conclusion: Evidence for the utility of a CYP2C19 AS system is provided, for which the accuracy can be further improved by means of comprehensive genotyping and substrate specific modification.

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Section: Cyp2c19 Comparison Between Predicted and Measured Phenotypecontrasting

confidence: 87%

Section: Phenotypingmentioning

confidence: 99%

Evaluation of Predictive Cyp2C19 Genotyping Assays Relative to Measured Phenotype in a South African Cohort

et al. 2015

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“…The phenotypes are classified using metabolic ratios of OME hydroxylation, calculated with OME and HOME plasma concentrations 3 hours after a single oral administration of 20 mg OME (Linden et al, 2007). This indicator is named metabolic ratio (MR) and usually presents a normal distribution on tested populations (Tamminga et al, 2001). MR values below 0.12 are found in ultra-extensive metabolizers (UE) and above 4.0 in poor metabolizers (PM), being classified as extensive metabolizers (EM) the individuals with intermediate values (González et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Relation between CYP2C19 phenotype and genotype in a group of Brazilian volunteers

Linden

Ziulkoski

Tonello

et al. 2009

Braz. J. Pharm. Sci.

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The CYP2C19 gene presents polymorphism affecting the pharmacokinetics of several drugs of clinical importance. The purpose of this study was to investigate the correlation between CYP2C19 genotype and metabolic phenotype in a group of 38 Brazilian volunteers, evaluating the phenotype prediction capacity of the genotyping procedure. For CYP2C19 phenotyping, omeprazole was used as the probe drug, using the hydroxylation metabolic ratio as the phenotypic indicator. Venous blood samples were drawn before and three hours after an oral administration of 20 mg omeprazole. The plasma concentrations of omeprazole and hydroxy-omeprazole were determined by high performance liquid chromatography. The genotyping assay was carried out using a Real-Time-PCR-based assay, identifying the alleles *1 (completely functional), *2, *3 and *4 (null). The phenotyping procedure estimated the presence of 4 poor, 34 extensive and 1 ultra-extensive metabolizer. The genotyping identified 4 poor, 23 extensive and 11 intensive metabolizers. The groups of volunteers classified according to the number of active alleles of CYP2C19 had significant differences in the metabolic ratios of omeprazole hydroxylation. However, volunteers exhibiting the same number of active alleles presented different phenotypes. Therefore, the phenotyping of CYP2C19 is a more promising alternative to dose individualization of CYP2C19 substrate drugs.Uniterms: Metabolic phenotyping. Metabolic genotyping. CYP2C19 gene.O gene CYP2C19 apresenta polimorfismo genético, com impacto importante na farmacocinética de diversos fármacos de importância clínica. O objetivo deste estudo foi avaliar a correlação entre genótipo e fenótipo de CYP2C19 em um grupo de 38 voluntários brasileiros, avaliando a capacidade de predição do fenótipo a partir de testes de genotipagem. Para a fenotipagem, utilizou-se omeprazol (OME) como fármaco-sonda para CYP2C19, empregando sua razão metabólica de hidroxilação como indicador fenotípico. Amostras de sangue foram coletadas antes e três horas após a administração oral de 20mg do fármaco. As concentrações plasmáticas de OME e seu metabólito foram determinadas por cromatografia líquida de alta eficiência. A genotipagem de CYP2C19 foi realizada através de ensaio baseado na reação em cadeia da polimerase em tempo real, identificando os alelos *1 (completamente funcional),*2 e *3 (nulos). Pela fenotipagem foi possível estimar a presença de 3 metabolizadores lentos, 34 rápidos e 1 ultra-rápido; enquanto pela genotipagem foi determinada a presença de 4 metabolizadores lentos, 23 rápidos e 11 intermediários. Os grupos de voluntários classificados de acordo com o número de alelos ativos apresentaram diferenças significativas entre as razões metabólicas de hidroxilação de omeprazol. Entretanto, indivíduos com o mesmo genótipo apresentaram fenótipos diferentes. Desta forma, a fenotipagem apresenta-se como alternativa mais promissora para a individualização das doses de fármacos substratos de CYP2C19.Unitermos: Fenotipagem metabólica. Genotipagem metabólica. Gen...

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“…Usually, an oral dose of 20 to 40 mg of omeprazole is orally administered and a blood sample is collected after 3 h and metabolic ratios are calculated based on HOME, OME and OMES plasma concentrations. [13][14][15] Knowledge of an individual phenotype for metabolizing enzymes can be useful in the adjustment of dosage regimen in pharmacotherapy. Van der Weide et al 16 have observed consistent relationship between metabolic ratios for amitriptyline with CYP2C19 genotype.…”

Section: Introductionmentioning

confidence: 99%

“…5 Several studies had used OME as a phenotyping probe for CYP2C19 and CYP3A4. [10][11][12][13][14] Three major phenotypes have been reported: poor metabolizer (PM), extensive metabolizer (EM) and ultra rapid metabolizer (UM). These phenotypes can be classified using metabolic ratios of omeprazole after oral administration.…”

Section: Introductionmentioning

confidence: 99%

Simultaneous determination of omeprazole, hydroxyomeprazole and omeprazole sulphone in human plasma by isocratic HPLC-DAD: application to the phenotyping of CYP2C19 and CYP3A4 in brazilian volunteers

Linden

Ziulkoski

Wingert

et al. 2007

J. Braz. Chem. Soc.

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Foi desenvolvido um método simples para a determinação simultânea de omeprazol (OME), 5-hidroxiomeprazol (HOME) e omeprazol sulfona (OMES) por meio de CLAE-DAD, utilizando coluna de fase reversa e eluição isocrática. O método proposto avaliou polimorfismos genéticos de CYP2C19 e CYP3A4 utilizando omeprazol como fármaco sonda em um grupo de voluntários brasileiros. OME, HOME e OMES foram extraídos de amostras de plasma com tampão Tris pH 9,5 (0,2 mol L -1 ) e acetato de etila. A separação por Cromatografia Líquida de Alta Eficiência (CLAE) foi realizada com uma coluna Shim-Pack RP-18e (150 × 4,6 mm d.i., 5 μm), com acetonitrila-tampão fosfato pH 7,6 (24:76, v/v) como fase móvel e tempo total da corrida de 15 min. Os tempos de retenção foram 2,7 min para o padrão interno (sulpirida), 4,1 min para HOME, 11,6 minutos para OME e 12,6 min para OMES. A detecção dos analitos (UV a 302 nm) foi linear na faixa de 25 a 1000 ng mL -1 . As recuperações absolutas variaram de 64,3 a 73,2% para todos os analitos. Um grupo de 38 voluntários sadios brasileiros foi fenotipado com esse método após a ingestão de uma dose oral única de 20 mg de omeprazol. O método apresentou precisão e exatidão adequadas, com limite de quantificação de 25 ng mL -1 para OME e seus metabólitos, o que permitiu a identificação de metabolizadores ultra-rápidos tanto para CYP2C19 quanto para CYP3A4, aproveitando as vantagens inerentes à identificação seletiva oferecida pelos detectores de arranjo de diodos.A simple HPLC-DAD method using a reverse phase column and isocratic elution for the simultaneous determination of omeprazole (OME), 5-hydroxyomeprazole (HOME) and omeprazole sulphone (OMES) was developed. The proposed method was used to study CYP2C19 and CYP3A4 genetic polymorphisms using OME as the probe drug in a group of Brazilian volunteers. OME, HOME and OMES were extracted from plasma samples with Tris buffer pH 9.5 (0.2 mol L -1 ) and ethyl acetate. HPLC separation was achieved using a Shim-Pack RP-18e (150 × 4.6 mm i.d., 5 μm) column, with acetonitrile phosphate buffer pH 7.6 (24:76) as mobile phase and total run time of 15 min. Retention times were 2.7 min for internal standard (sulpiride), 4.1 min for HOME, 11.6 min for OME and 12.6 min for OMES. Detection (UV at 302 nm) of analytes was linear in the range from 25 to 1000 ng mL -1 . Extraction recoveries were in the range of 64.3 to 73.2% for all analytes. A group of 38 Brazilian healthy volunteers was phenotyped with this method, after a single oral dose of 20 mg omeprazole. The method presented adequate accuracy and precision, with limit of quantification of 25 ng mL -1 for omeprazole and metabolites, which allowed the identification of ultra-rapid metabolizers for both CYP2C19 and CYP3A4 and took advantage of the selective identification offered by diode-array detectors.

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An optimized methodology for combined phenotyping and genotyping on CYP2D6 and CYP2C19

Cited by 34 publications

References 0 publications

Evaluation of Predictive Cyp2C19 Genotyping Assays Relative to Measured Phenotype in a South African Cohort

Evaluation of Predictive Cyp2C19 Genotyping Assays Relative to Measured Phenotype in a South African Cohort

Relation between CYP2C19 phenotype and genotype in a group of Brazilian volunteers

Simultaneous determination of omeprazole, hydroxyomeprazole and omeprazole sulphone in human plasma by isocratic HPLC-DAD: application to the phenotyping of CYP2C19 and CYP3A4 in brazilian volunteers

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