Simultaneous LC–MS/MS Quantification of P-Glycoprotein and Cytochrome P450 Probe Substrates and Their Metabolites in DBS and Plasma

Bosilkovska, Marija; Samer, Caroline Flora; Walder, Bernhard; Daali, Youssef

doi:10.4155/bio.13.289

Cited by 52 publications

(76 citation statements)

References 32 publications

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“…In contrast to Donzelli et al, the higher volume, combined with the use of more sensitive equipment, allowed quantification of all probe drugs and corresponding metabolites in DBS. Single point metabolite/parent drug ratios at 2 h for CYP1A2 and CYP3A4 and at 3 h for CYP2B6, CYP2C9 and CYP2D6, and the AUC 2,3,6 metabolite/parent drug ratio for CYP2C19 showed acceptable Spearman rank correlation coefficients with AUC last ratios in plasma, both when the cocktail was administered alone or in combination with CYP450 inhibitor and inducer drugs [43,44].…”

Section: Dried Blood Spotsmentioning

confidence: 94%

Alternative Sampling Strategies for Cytochrome P450 Phenotyping

2015

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Interindividual variability in the expression and function of drug metabolizing cytochrome P (CYP) 450 enzymes, determined by a combination of genetic, non-genetic and environmental parameters, is a major source of variable drug response. Phenotyping by administration of a selective enzyme substrate, followed by the determination of a specific phenotyping metric, is an appropriate approach to assess the in vivo activity of CYP450 enzymes, as it takes into account all influencing factors. A phenotyping protocol should be as simple and convenient as possible. Typically, phenotyping metrics are determined in traditional matrices, such as blood, plasma or urine. Several sampling strategies have been proposed as an alternative for these traditional sampling techniques.In this review, we provide a comprehensive overview of available methods using dried blood spots, hair, oral fluid, exhaled breath and sweat for in vivo CYP450 phenotyping. We discuss the relation between phenotyping metrics measured in these samples and those in conventional matrices, along with the advantages and limitations of the alternative sampling techniques. Reliable phenotyping procedures for several clinically relevant CYP450 enzymes, including CYP1A2, CYP2C19 and CYP2D6, are currently available for oral fluid, breath or dried blood spots, while additional studies are needed for other CYP450 isoforms, such as CYP3A4. The role of hair analysis for this purpose remains to be established. Being non-or minimally invasive, these sampling strategies provide convenient and patient-friendly alternatives for classical phenotyping procedures, which may contribute to the implementation of CYP450 phenotyping in clinical practice. 4 Key Points Phenotyping by administration of a selective probe drug, followed by determination of a specific phenotyping metric, allows to assess the in vivo enzyme activity of CYP450 enzymes, taking into account genetic, non-genetic and environmental influencing factors. In addition to classical sampling techniques, such as blood or urine collection, reliable phenotyping procedures for several clinically relevant CYP450 enzymes are currently available for oral fluid, breath and dried blood spots.

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Section: Dried Blood Spotsmentioning

confidence: 94%

Alternative Sampling Strategies for Cytochrome P450 Phenotyping

2015

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“…In this study, which is the largest published DBS-based phenotyping study to date, caffeine and its main metabolite paraxanthine were determined in capillary DBS, venous DBS, whole blood and plasma in the context of CYP1A2 phenotyping. Although a proof-of-principle of DBS-based CYP phenotyping is already available [20][21][22][23][24], all published studies had small data sets (n  16) and did not include a systematic evaluation of DBS-specific parameters. Moreover, with a single exception [23], all studies started from volumetrically applied DBS, an approach that is difficult to sustain when envisaging patient self-sampling at home.…”

Section: Discussionmentioning

confidence: 99%

“…Although we and others [20][21][22][23][24] demonstrated that DBS can be used for phenotyping CYP enzymes, no report has evaluated the impact of variation of these parameters on the phenotyping index. First, we did not observe significant differences between caffeine and paraxanthine concentrations measured in discs punched out peripherally versus centrally, irrespective of the Hct (Supplementary Figure S7).…”

Section: Dbs-specific Parametersmentioning

confidence: 99%

“…Very recently, two groups reported on the use of a cocktail approach to simultaneously phenotype multiple enzymes, including CYP1A2, in DBS [22,23]. However, all these studies were conducted in a very limited number of volunteers (n ≤ 16), hampering thorough statistical evaluation.…”

Section: Introductionmentioning

confidence: 99%

“…However, all these studies were conducted in a very limited number of volunteers (n ≤ 16), hampering thorough statistical evaluation. In all cases, except for the study by Donzelli et al [23], blood spots were volumetrically applied to the filter paper in a controlled environment [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

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Why Dried Blood Spots Are an Ideal Tool for CYP1A2 Phenotyping

2014

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Background and ObjectiveDried blood spot (DBS) sampling has gained wide interest in bioanalysis during the last decade. Also in pharmacokinetic and phenotyping studies, DBS-based sampling has already been successfully applied. However, all available phenotyping studies used small data sets and did not include a systematic evaluation of DBS-specific parameters. The latter is important since several of these factors still challenge the breakthrough of DBS in routine practice. In this study, caffeine and paraxanthine are determined in capillary DBS, venous DBS, whole blood and plasma for CYP1A2 phenotyping (CYP; cytochrome P450). The aim of this study was to explore the usefulness of DBS as a tool for CYP1A2 phenotyping. MethodsA CYP1A2 phenotyping study was conducted in seventy-three healthy volunteers, who received a 150 mg oral dose of caffeine. Six hours post-administration, caffeine and paraxanthine concentrations and paraxanthine:caffeine molar concentration ratios, i.e. the actual CYP1A2 phenotyping indices, were determined in capillary DBS (obtained by non-volumetric application, direct from the fingertip), venous DBS, whole blood and plasma. Furthermore, the impact of DBS-specific parameters, including hematocrit, volume spotted and punch location, was evaluated. ResultsConcentrations of caffeine and paraxanthine in capillary DBS were on average 12.7 respectively 13.8 % lower than those in venous DBS and 31.5 respectively 33.1 % lower than those in plasma. While these differences were statistically significant (p < 0.001), no significant difference was observed between the paraxanthine:caffeine molar ratios in the distinct evaluated matrices (p ≥ 0.053). This ratio also alleviated the impact of hematocrit and volume spotted. ConclusionsUsing the largest DBS-based phenotyping study to date, we have demonstrated that CYP1A2 phenotyping in capillary DBS is a valid and convenient alternative for the classical plasma-based approach. Additionally, we have provided an objective basis as to why DBS are an ideal tool for CYP1A2 phenotyping.  While capillary DBS concentrations of caffeine and paraxanthine differed significantly from those in venous blood and plasma and were impacted by hematocrit and blood volume spotted, the paraxanthine:caffeine molar ratio essentially remained unaffected. Capillary DBS-based CYP1A2 phenotyping proved to be a valid and convenient alternative for the classical plasma-based approach.4

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Impact of Acute Inflammation on Cytochromes P450 Activity Assessed by the Geneva Cocktail

Lenoir

Daali

Rollason

et al. 2021

Clin Pharma and Therapeutics

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Cytochromes P450 (CYP) are subject to important interindividual variability in their activity due to genetic and environmental factors and some diseases. Limited human data support the idea that inflammation downregulates CYP activities. Our study aimed to evaluate the impact of orthopedic surgery (acute inflammation model) on the activity of six human CYP. This prospective observational study was conducted in 30 patients who underwent elective hip surgery at the Geneva University Hospitals in Switzerland. The Geneva phenotyping cocktail containing caffeine, bupropion, flurbiprofen, omeprazole, dextromethorphan, and midazolam as probe drugs respectively assessing CYP1A2, 2B6, 2C9, 2C19, 2D6, and 3A activities was administered orally before surgery, day 1 (D1) and 3 (D3) postsurgery and at discharge. Capillary blood samples were collected 2 hours after cocktail intake to assess metabolic ratios (MRs). Serum inflammatory markers (CRP, IL-6, IL-1β, TNF-α, and IFN-γ) were also measured in blood. CYP1A2 MRs decreased by 53% (P < 0.0001) between baseline and the nadir at D1. CYP2C19 and CYP3A activities (MRs) decreased by 57% (P = 0.0002) and 61% (P < 0.0001), respectively, with the nadir at D3. CYP2B6 and CYP2C9 MRs increased by 120% (P < 0.0001) and 79% (P = 0.018), respectively, and peaked at D1. Surgery did not have a significant impact on CYP2D6 MR. Hip surgery was a good acute inflammation model as CRP, IL-6, and TNF-α peak levels were reached between D1 and day 2 (D2). Acute inflammation modulated CYP activity in an isoform-specific manner, with different magnitudes and kinetics. Acute inflammation may thus have a clinically relevant impact on the pharmacokinetics of these CYP substrates.

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Simultaneous LC–MS/MS Quantification of P-Glycoprotein and Cytochrome P450 Probe Substrates and Their Metabolites in DBS and Plasma

Abstract: Due to its low-invasiveness, simple sample collection and minimal sample preparation, DBS represents a suitable method to simultaneously monitor in vivo activities of P-gp and CYP.

Cited by 52 publications

References 32 publications

Alternative Sampling Strategies for Cytochrome P450 Phenotyping

Alternative Sampling Strategies for Cytochrome P450 Phenotyping

Why Dried Blood Spots Are an Ideal Tool for CYP1A2 Phenotyping

Impact of Acute Inflammation on Cytochromes P450 Activity Assessed by the Geneva Cocktail

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