Variance of Oral Methadone Dosage: Description of Implicated Factors (METHADOSE)
The purpose of this study is to describe clinical, pharmacokinetic and genetic factors associated with the variance of oral methadone dosage for patients at the steady state of heroin dependence maintenance treatment. The hypothesis is that the investigators can predict 70% of the variance with few factors, including CYP 3A4 function measured with oral midazolam challenge.
|Study Design:||Observational Model: Case-Only
Time Perspective: Cross-Sectional
|Official Title:||Factors Associated With the Variance of Oral Methadone Dosage at Steady State of Maintenance Treatment: Description of Bio-markers of Phenotype and Genotype.|
- Functional activity CYP3A4 [ Time Frame: Day15 ] [ Designated as safety issue: No ]Functional activity CYP3A4 as measured by the ratio of metabolite / parent drug provided by the functional test the oral midazolam.
Biospecimen Retention: Samples With DNA
serum: orosomucoid, methadone dosage, OH midazolam/midazola ratio
DNA: CYPs, MDR1, OPRM1, COMT
|Study Start Date:||December 2008|
|Study Completion Date:||May 2013|
|Primary Completion Date:||April 2013 (Final data collection date for primary outcome measure)|
Patients at the steady state of methadone maintenance treatment may receive oral dosage ranging from 5 to 130 mg per day in our clinical practice. This study is aimed at providing a comprehensive cross-sectional description of factors involved in this variance:
- comorbidity with addictive and psychiatric disorders
- severity of pre-existing heroin dependence
- function of CYP 3A4 enzyme assessed with oral midazolam challenge
- genetic polymorphisms of enzymes implicated in methadone pharmacokinetic and pharmacodynamic (CYPs, MDR1, OPRM1, COMT)
The expected result is a predictive equation of oral methadone dosage at steady state.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00894452
|hospital Lariboisière-Fernand-WidalCity: PARIS|
|Paris, France, 75010|
|Principal Investigator:||Florence VORSPAN, MD||Assistance Publique - Hôpitaux de Paris|