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Variance of Oral Methadone Dosage: Description of Implicated Factors (METHADOSE)

This study has been completed.
Information provided by (Responsible Party):
Assistance Publique - Hôpitaux de Paris Identifier:
First received: March 31, 2009
Last updated: September 28, 2016
Last verified: September 2016
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.

Heroin Dependence

Study Type: Observational
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.

Resource links provided by NLM:

Further study details as provided by Assistance Publique - Hôpitaux de Paris:

Primary Outcome Measures:
  • Functional activity CYP3A4 [ Time Frame: Day15 ]
    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


Enrollment: 210
Study Start Date: December 2008
Study Completion Date: May 2013
Primary Completion Date: April 2013 (Final data collection date for primary outcome measure)
Detailed Description:

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.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
Defined population: participants or population are selected based on predefined criteria

Inclusion Criteria:

  • heroin dependence
  • under maintenance treatment with methadone
  • at steady state: stable oral methadone dosage since 3 months at least

Exclusion Criteria:

  • current heroin dependence or abuse
  • current cocaine and/or alcohol and/or sedatives dependence
  • pregnancy
  Contacts and Locations
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Please refer to this study by its identifier: NCT00894452

hospital Lariboisière-Fernand-WidalCity: PARIS
Paris, France, 75010
Sponsors and Collaborators
Assistance Publique - Hôpitaux de Paris
Principal Investigator: Florence VORSPAN, MD Assistance Publique - Hôpitaux de Paris
  More Information


Responsible Party: Assistance Publique - Hôpitaux de Paris Identifier: NCT00894452     History of Changes
Other Study ID Numbers: P070603
Study First Received: March 31, 2009
Last Updated: September 28, 2016

Keywords provided by Assistance Publique - Hôpitaux de Paris:
Midazolam challenge

Additional relevant MeSH terms:
Heroin Dependence
Opioid-Related Disorders
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Analgesics, Opioid
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents
Antitussive Agents
Respiratory System Agents processed this record on September 19, 2017