Cocktail Approach for Cytochrome P450 and P-glycoprotein Activity Assessment Using Dried Blood Spot

Study Overview
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Brief Summary
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Phenotyping is an approach largely used for the evaluation of the activity of cytochromes and transporters in vivo. It consists of the administration of probe substances metabolised by a specific cytochrome or transported by P-glycoprotein (P-gp) for example, followed by the determination of a metabolic ratio or the evaluation of the plasmatic or urinary concentrations of the probe substances. The administration of a cocktail containing several probe substances allows the simultaneous evaluation of the activity of several cytochromes and P-gp in a single test. The aim of this project is the validation of a phenotyping cocktail of low dose probe drugs for the assessment of cytochrome P450 and P-gp activities by simple capillary blood sampling and dried blood spot (DBS) analysis. The cocktail consists of caffeine, bupropion, flurbiprofen, omeprazole, dextromethorphan, midazolam and fexofenadine for the simultaneous phenotyping of CYP1A2, CYP2B6, CYP2C9, CAP2C19, CYP2D6, CYP3A4 and P-gp, respectively. The modulation of the activity of cytochromes or P-gp will be evaluated by the administration of inhibitors (fluvoxamine, voriconazole, quinidine) or inducer (rifampicin) of the metabolic pathways or the P-gp mediated transport.

Conditions
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Healthy Volunteers

Intervention / Treatment
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* Drug: Cocktail probe drugs


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy male volunteers aged from 18 to 60 years BMI between 18 and 25 Understanding of French language and able to give a written inform consent. Exclusion Criteria: Smoker Taking drugs which alter CYPs activity Renal or hepatic impairment Medical history of porphyria Medical history of chronic alcoholism or abuse of psychoactive drugs Liver transplantation Sensitivity to any of the drugs used Wearing contact lenses (risk of coloration with rifampicin) ECG showing long QT interval (>0.46sec) Alteration of hepatic tests Presenting genetic polymorphism of poor CYP 2B6, 2C9, 2C19, 2D6 metabolisers

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: CYP1A2, 2B6, 2C9, 2C19, 3A4 inhibitors<br>Oral intake of fluvoxamine (50 mg per day during 2 days) and voriconazole (400 mg) before oral intake of the cocktail probe drugs | Drug: Cocktail probe drugs<br> <br> * Other names: Caffeine (a cup of coffee);|
| Active Comparator: CYP2D6 and P-gp inhibitor<br>Oral intake of quinidine (200 mg) before oral intake of the cocktail probe drugs | Drug: Cocktail probe drugs<br> <br> * Other names: Caffeine (a cup of coffee);|
| Active Comparator: CYPs and P-gp inducer<br>Oral intake of rifampicin (600 mg per day during 7 days) before oral intake of the cocktail probe drugs | Drug: Cocktail probe drugs<br> <br> * Other names: Caffeine (a cup of coffee);|
| Experimental: Probe cocktail alone<br>Oral intake of the cocktail probe drugs : bupropion 25 mg flurbiprofen 25 mg omeprazole 5 mg dextromethorphan 5 mg midazolam 1 mg fexofenadine 25mg Caffeine (a cup of coffee) | Drug: Cocktail probe drugs<br> <br> * Other names: Caffeine (a cup of coffee);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Probe cocktail drugs plasma and capillary concentrations in presence/absence of CYP1A2,2B6, 2C9, 2C19, 2D6, 3A4 and P-gp inhibitor or inducer |  | 4 singles days spaced out with one week wash-out periods | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| correlation between plasma or urine and capillary concentrations for each probe cocktail drug |  | 4 singles days spaced out with one week wash-out periods | 
| comparison. between genotype and phenotype for each enzyme |  | one day |