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Geneva cocktail for cytochrome p450 and P-glycoprotein activity assessment using dried blood spots.

Bosilkovska M, Samer CF, Déglon J, Rebsamen M, Staub C, Dayer P, Walder B, Desmeules JA, Daali Y - Clin. Pharmacol. Ther. (2014)

Bottom Line: In session 4, subjects received the cocktail after a 7-day pretreatment with the inducer rifampicin.The pharmacokinetic profiles of the drugs were comparable in DBS and plasma.Important modulation of CYP and P-gp activities was observed in the presence of inhibitors and the inducer.

View Article: PubMed Central - PubMed

Affiliation: Division of Clinical Pharmacology and Toxicology, Geneva University Hospitals, Geneva, Switzerland.

ABSTRACT
The suitability of the capillary dried blood spot (DBS) sampling method was assessed for simultaneous phenotyping of cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp) using a cocktail approach. Ten volunteers received an oral cocktail capsule containing low doses of the probes bupropion (CYP2B6), flurbiprofen (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), midazolam (CYP3A), and fexofenadine (P-gp) with coffee/Coke (CYP1A2) on four occasions. They received the cocktail alone (session 1), and with the CYP inhibitors fluvoxamine and voriconazole (session 2) and quinidine (session 3). In session 4, subjects received the cocktail after a 7-day pretreatment with the inducer rifampicin. The concentrations of probes/metabolites were determined in DBS and plasma using a single liquid chromatography-tandem mass spectrometry method. The pharmacokinetic profiles of the drugs were comparable in DBS and plasma. Important modulation of CYP and P-gp activities was observed in the presence of inhibitors and the inducer. Minimally invasive one- and three-point (at 2, 3, and 6 h) DBS-sampling methods were found to reliably reflect CYP and P-gp activities at each session.

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Concentration–time profiles for CYP probe substrates (circles) and their metabolites (triangles) obtained in 10 µl of capillary DBS (dashed lines) and venous plasma samples (continuous lines) after oral administration of cocktail alone (left column), in the presence of inhibitor(s) (middle), or in the presence of an inducer (right) in 10 healthy volunteers. CYP1A2 profile is presented only for volunteers who received coffee (n = 6); CYP2D6 profiles are presented only for EMs and UMs (n = 7). Error bars represent SD. CYP, cytochrome P450; DBS, dried blood spot; EM, extensive metabolizer; UM, ultrarapid metabolizer.
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fig1: Concentration–time profiles for CYP probe substrates (circles) and their metabolites (triangles) obtained in 10 µl of capillary DBS (dashed lines) and venous plasma samples (continuous lines) after oral administration of cocktail alone (left column), in the presence of inhibitor(s) (middle), or in the presence of an inducer (right) in 10 healthy volunteers. CYP1A2 profile is presented only for volunteers who received coffee (n = 6); CYP2D6 profiles are presented only for EMs and UMs (n = 7). Error bars represent SD. CYP, cytochrome P450; DBS, dried blood spot; EM, extensive metabolizer; UM, ultrarapid metabolizer.

Mentions: Pharmacokinetic profiles of all the CYP-specific substrates and metabolites were comparable in DBS and plasma in terms of distribution and elimination (Figure 1). Caffeine AUCs for the four volunteers who received Coke were approximately four times lower than the AUCs of those who received coffee; however, the paraxanthine/caffeine AUC ratios were similar, and therefore these were analyzed together (Table 1). For flurbiprofen, midazolam, and omeprazole, maximum plasma concentration (Cmax) and AUC were proportionally lower in DBS than in plasma, with an approximate mean ratio of 0.6 corresponding to the dilution factor due to the presence of blood cells. Bupropion or dextromethorphan Cmax and AUC were higher in DBS in comparison with plasma, probably as a result of blood cell partitioning (Figure 1 and Table 1). For fexofenadine, a similar pharmacokinetic profile was observed in DBS and plasma, with no statistically significant differences between the two matrices in terms of half-lives or time to maximum concentration (Tmax) at each session, whereas Cmax and AUC values were slightly higher in plasma, with a blood to plasma ratio of ~0.9 (Figure 2 and Table 2).


Geneva cocktail for cytochrome p450 and P-glycoprotein activity assessment using dried blood spots.

Bosilkovska M, Samer CF, Déglon J, Rebsamen M, Staub C, Dayer P, Walder B, Desmeules JA, Daali Y - Clin. Pharmacol. Ther. (2014)

Concentration–time profiles for CYP probe substrates (circles) and their metabolites (triangles) obtained in 10 µl of capillary DBS (dashed lines) and venous plasma samples (continuous lines) after oral administration of cocktail alone (left column), in the presence of inhibitor(s) (middle), or in the presence of an inducer (right) in 10 healthy volunteers. CYP1A2 profile is presented only for volunteers who received coffee (n = 6); CYP2D6 profiles are presented only for EMs and UMs (n = 7). Error bars represent SD. CYP, cytochrome P450; DBS, dried blood spot; EM, extensive metabolizer; UM, ultrarapid metabolizer.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4151019&req=5

fig1: Concentration–time profiles for CYP probe substrates (circles) and their metabolites (triangles) obtained in 10 µl of capillary DBS (dashed lines) and venous plasma samples (continuous lines) after oral administration of cocktail alone (left column), in the presence of inhibitor(s) (middle), or in the presence of an inducer (right) in 10 healthy volunteers. CYP1A2 profile is presented only for volunteers who received coffee (n = 6); CYP2D6 profiles are presented only for EMs and UMs (n = 7). Error bars represent SD. CYP, cytochrome P450; DBS, dried blood spot; EM, extensive metabolizer; UM, ultrarapid metabolizer.
Mentions: Pharmacokinetic profiles of all the CYP-specific substrates and metabolites were comparable in DBS and plasma in terms of distribution and elimination (Figure 1). Caffeine AUCs for the four volunteers who received Coke were approximately four times lower than the AUCs of those who received coffee; however, the paraxanthine/caffeine AUC ratios were similar, and therefore these were analyzed together (Table 1). For flurbiprofen, midazolam, and omeprazole, maximum plasma concentration (Cmax) and AUC were proportionally lower in DBS than in plasma, with an approximate mean ratio of 0.6 corresponding to the dilution factor due to the presence of blood cells. Bupropion or dextromethorphan Cmax and AUC were higher in DBS in comparison with plasma, probably as a result of blood cell partitioning (Figure 1 and Table 1). For fexofenadine, a similar pharmacokinetic profile was observed in DBS and plasma, with no statistically significant differences between the two matrices in terms of half-lives or time to maximum concentration (Tmax) at each session, whereas Cmax and AUC values were slightly higher in plasma, with a blood to plasma ratio of ~0.9 (Figure 2 and Table 2).

Bottom Line: In session 4, subjects received the cocktail after a 7-day pretreatment with the inducer rifampicin.The pharmacokinetic profiles of the drugs were comparable in DBS and plasma.Important modulation of CYP and P-gp activities was observed in the presence of inhibitors and the inducer.

View Article: PubMed Central - PubMed

Affiliation: Division of Clinical Pharmacology and Toxicology, Geneva University Hospitals, Geneva, Switzerland.

ABSTRACT
The suitability of the capillary dried blood spot (DBS) sampling method was assessed for simultaneous phenotyping of cytochrome P450 (CYP) enzymes and P-glycoprotein (P-gp) using a cocktail approach. Ten volunteers received an oral cocktail capsule containing low doses of the probes bupropion (CYP2B6), flurbiprofen (CYP2C9), omeprazole (CYP2C19), dextromethorphan (CYP2D6), midazolam (CYP3A), and fexofenadine (P-gp) with coffee/Coke (CYP1A2) on four occasions. They received the cocktail alone (session 1), and with the CYP inhibitors fluvoxamine and voriconazole (session 2) and quinidine (session 3). In session 4, subjects received the cocktail after a 7-day pretreatment with the inducer rifampicin. The concentrations of probes/metabolites were determined in DBS and plasma using a single liquid chromatography-tandem mass spectrometry method. The pharmacokinetic profiles of the drugs were comparable in DBS and plasma. Important modulation of CYP and P-gp activities was observed in the presence of inhibitors and the inducer. Minimally invasive one- and three-point (at 2, 3, and 6 h) DBS-sampling methods were found to reliably reflect CYP and P-gp activities at each session.

Show MeSH
Related in: MedlinePlus