Opioid Agonist and Antagonist Effects on Opioid Dependence

This study has been terminated.
(Study terminated due to halt in funding; may resume recruiting in future)
Johns Hopkins University
Information provided by:
National Institute on Drug Abuse (NIDA)
ClinicalTrials.gov Identifier:
First received: September 1, 2005
Last updated: July 10, 2007
Last verified: July 2007
The purpose of this study is to examine the acute agonist and antagonist effects of a full opioid agonist medication, an opioid antagonist medication, and a partial opioid agonist medication in individuals who have different levels of physical opioid dependence.

Condition Intervention Phase
Opioid-Related Disorders
Drug: Methadone
Drug: Full opioid agonist
Drug: Partial opioid agonist
Drug: Opioid antagonist
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Pharmacodynamics Study
Intervention Model: Parallel Assignment
Masking: Double-Blind
Primary Purpose: Treatment
Official Title: The Variability of Agonist and Antagonist Effects as a Function of Level of Physical Dependence

Further study details as provided by National Institute on Drug Abuse (NIDA):

Primary Outcome Measures:
  • Opiate withdrawal [ Time Frame: up to one day ]
  • Opiate agonist symptoms [ Time Frame: up to one day ]
  • Physiologic measures [ Time Frame: up to one day ]

Estimated Enrollment: 16
Study Start Date: January 2004
Estimated Study Completion Date: February 2006
Detailed Description:

The pharmacological effects of opioids in opioid dependent individuals can vary as a function of the characteristics of the opioid being studied (e.g., whether it is an agonist, partial agonist, or antagonist; the dose administered; and the route of administration). Another important set of factors influencing the effects produced by opioids is the characteristics of the organism to which the opioid is being administered. One such characteristic is the level of physical dependence in individuals.

Participants in this study will be maintained on different dose levels of an opioid agonist (methadone). The participant will be challenged with a prototypic opioid agonist, antagonist, and a mixed agonist-antagonist with partial agonist features in order to determine the effects that each has on the human body.


Ages Eligible for Study:   18 Years to 55 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Active opioid dependence
  • Qualifies for opioid agonist treatment (e.g., methadone or buprenorphine)
  • Fulfills DSM-IV diagnostic criteria for opioid dependence

Exclusion Criteria:

  • Significant medical problems, including insulin dependent diabetes mellitus
  • Non-substance use psychiatric disorders (e.g., schizophrenia)
  • Currently seeking treatment for substance abuse
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00142727

United States, Maryland
Johns Hopkins University (BPRU) Bayview Campus
Baltimore, Maryland, United States, 21224 6823
Sponsors and Collaborators
National Institute on Drug Abuse (NIDA)
Johns Hopkins University
Principal Investigator: Eric C. Strain, MD Johns Hopkins University
  More Information

ClinicalTrials.gov Identifier: NCT00142727     History of Changes
Other Study ID Numbers: NIDA-08045-6  R01-08045-6  DPMC 
Study First Received: September 1, 2005
Last Updated: July 10, 2007
Health Authority: United States: Federal Government
United States: Food and Drug Administration

Additional relevant MeSH terms:
Opioid-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Substance-Related Disorders
Analgesics, Opioid
Narcotic Antagonists
Central Nervous System Depressants
Peripheral Nervous System Agents
Physiological Effects of Drugs
Sensory System Agents

ClinicalTrials.gov processed this record on May 26, 2016