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Isoflurane at Subanesthetic Concentrations - 6

This study has been completed.
National Institute on Drug Abuse (NIDA)
Information provided by (Responsible Party):
University of Chicago Identifier:
First received: September 20, 1999
Last updated: May 26, 2015
Last verified: May 2015
The purpose of this study is to conduct experiments to examine subjective and reinforcing effects of nitrous oxide. Mood altering and psychomotor effects will be tested on non-drug abusers and preference procedures will be used to assess reinforcing effects. To test the hypothesis that isoflurane at subanesthetic concentrations does not reduce cold-water immersion pain in healthy volunteers.

Condition Intervention Phase
Opioid-Related Disorders
Substance-Related Disorders
Drug: 40% Nitrous oxide
Other: Sham comparator
Drug: 0.2% isoflurane
Drug: 0.4% isoflurane
Drug: 0.6% isoflurane
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single Blind (Participant)
Primary Purpose: Treatment
Official Title: Isoflurane at Subanesthetic Concentrations

Resource links provided by NLM:

Further study details as provided by University of Chicago:

Primary Outcome Measures:
  • Pain response [ Time Frame: Post inhalation ]
    Effects of inhaled isoflurane on pain from immersion of subject's arm in ice cold water. Nitrous oxide (40%) was used as a positive control to confirm sensitivity of the pain assay.

Enrollment: 10
Study Start Date: January 1995
Study Completion Date: September 1995
Primary Completion Date: September 1995 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Sham Comparator: 0% isoflurane Drug: 40% Nitrous oxide
Used as pain assay positive control
Other: Sham comparator
0% isoflurane in oxygen
Active Comparator: 0.2% isoflurane Drug: 40% Nitrous oxide
Used as pain assay positive control
Drug: 0.2% isoflurane
Active Comparator: 0.4% isoflurane Drug: 40% Nitrous oxide
Used as pain assay positive control
Drug: 0.4% isoflurane
Active Comparator: 0.6% isoflurane Drug: 40% Nitrous oxide
Used as pain assay positive control
Drug: 0.6% isoflurane


Ages Eligible for Study:   21 Years to 34 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
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Please refer to this study by its identifier: NCT00000254

United States, Illinois
University of Chicago, Anesthesia & Critical Care
Chicago, Illinois, United States, 60637
Sponsors and Collaborators
University of Chicago
National Institute on Drug Abuse (NIDA)
Principal Investigator: James Zacny, Ph.D. University of Chicago
  More Information

Anesthesiology, 1995, 83: A287

Responsible Party: University of Chicago Identifier: NCT00000254     History of Changes
Other Study ID Numbers: NIDA-08391-6
R01DA008391 ( US NIH Grant/Contract Award Number )
Study First Received: September 20, 1999
Last Updated: May 26, 2015

Keywords provided by University of Chicago:
general anesthetic
subjective effects
healthy volunteer

Additional relevant MeSH terms:
Substance-Related Disorders
Opioid-Related Disorders
Pathologic Processes
Chemically-Induced Disorders
Mental Disorders
Nitrous Oxide
Anesthetics, Inhalation
Anesthetics, General
Central Nervous System Depressants
Physiological Effects of Drugs
Analgesics, Non-Narcotic
Sensory System Agents
Peripheral Nervous System Agents processed this record on May 25, 2017