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Development of Cocktail for Measuring the Activity of Important Cytochrome P450 Enzymes

NCT00981929 · Status: TERMINATED · Phase: NA · Type: INTERVENTIONAL · Enrollment: 412

Last updated 2010-06-28

No results posted yet for this study

Summary

The Cytochrome P450 enzymes are responsible for the metabolism of a wide range of drugs and other xenobiotics. Genetic variants of the encoding P450 genes have shown to influence the rate of metabolism of many clinically used drugs.

The drugs tramadol, omeprazole, losartan, quinidine and caffeine reflect the activity of CYP2D6 (tramadol), CYP2C19 (omeprazole), CYP2C9 (losartan), CYP1A2 (caffeine) and CYP3A4/5 (quinidine).

The aim of the study is to investigate if the cocktail of tramadol, omeprazole, losartan and caffeine can be used to simultaneously determine the activity of CYP2D6, CYP2C19, CYP2C9 and CYP1A2. Furthermore, will the natural occurring 4-beta-hydroxy-cholesterol in the blood be measured as a metric for CYP3A4/5.

The study is divided in two. First part will include 12 healthy volunteers and consists of three arms separated by at least one week. In the first arm 50 mg of tramadol will be ingested and urine will be collected for 8 hours. In the second arm 20 mg omeprazole, 25 mg losartan and 200 mg caffeine will be ingested followed by 8 hours urine collection and a blood sample 4 hours after administration of the drugs. In the last arm 50 mg of tramadol, 20 mg omeprazole, 25 mg losartan and 200 mg caffeine will be ingested followed by 8 hours urine collection and a blood sample 4 hours after administration of the drugs.

Metabolic ratios will be calculated based on urine and plasma concentrations of the drugs and the relevant metabolites. Relevant genetic variants of the cytochrome P450 encoding genes will be determined.

If the metabolic ratios of the drugs are not significantly different between the arms, Second part of the study will be conducted.

This part is identical with the last arm and will include a maximum of 400 healthy volunteers: 50 mg of tramadol, 20 mg omeprazole, 25 mg losartan and 200 mg caffeine will be ingested followed by 8 hours urine collection and a blood sample 4 hours after administration of the drugs.

Conditions

  • Cytochrome P450 Phenotype and Genotype Metrics

Interventions

DRUG

Tramadol

50 mg single oral dose

DRUG

Omeprazole, losartan, caffeine

20 mg omeprazole 25 mg losartan 200 mg caffeine

DRUG

Tramadol, omeprazole, losartan, caffeine

50 mg tramadol 20 mg omeprazole 25 mg losartan 200 mg caffeine

Sponsors & Collaborators

  • Odense University Hospital

    collaborator OTHER

  • University of Southern Denmark

    lead OTHER

Study Design

Allocation
NON_RANDOMIZED
Purpose
SCREENING
Masking
NONE
Model
CROSSOVER

Eligibility

Min Age
18 Years
Max Age
65 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2009-09-30
Primary Completion
2009-12-31
Completion
2011-01-31

Countries

  • Denmark

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00981929 on ClinicalTrials.gov