NCT05142267 · Vanderbilt University Medical Center
Stress and Opioid Misuse Risk: The Role of Endogenous Opioid and Endocannabinoid Mechanisms
What this study is about
The purpose of this study is to see how stress influences the effects of opioid pain medications often used to help relieve back pain. The study will help to learn more about how high stress levels could increase risk for pain medication misuse.
View original scientific description
The purpose of this study is to see how stress influences the effects of opioid pain medications often used to help relieve back pain. The study will help to learn more about how high stress levels could increase risk for pain medication misuse.
Interventions
DRUG
Placebo
In randomized order (crossover) across 3 laboratory sessions, participants will undergo laboratory evoked thermal pain response testing with: 1) 0.13 mg/kg of oral oxycodone (in 1mg/ml syrup) plus 20ml i.v. saline placebo, 2) 8mg of i.v. naloxone (in 20ml saline vehicle) plus oral placebo syrup (quantity matching oxycodone syrup volume), or 3) 20ml i.v. saline placebo plus oral placebo syrup (quantity matching oxycodone syrup volume). Thermal pain testing utilizes a Medoc TSAII NeuroSensory Analyzer. This equipment is used to assess heat pain threshold and tolerance using an ascending method of limits protocol.
DRUG
Oxycodone
In randomized order (crossover) across 3 laboratory sessions, participants will undergo laboratory evoked thermal pain response testing with: 1) 0.13 mg/kg of oral oxycodone (in 1mg/ml syrup) plus 20ml i.v. saline placebo, 2) 8mg of i.v. naloxone (in 20ml saline vehicle) plus oral placebo syrup (quantity matching oxycodone syrup volume), or 3) 20ml i.v. saline placebo plus oral placebo syrup (quantity matching oxycodone syrup volume). Thermal pain testing utilizes a Medoc TSAII NeuroSensory Analyzer. This equipment is used to assess heat pain threshold and tolerance using an ascending method of limits protocol.
DRUG
Naloxone
In randomized order (crossover) across 3 laboratory sessions, participants will undergo laboratory evoked thermal pain response testing with: 1) 0.13 mg/kg of oral oxycodone (in 1mg/ml syrup) plus 20ml i.v. saline placebo, 2) 8mg of i.v. naloxone (in 20ml saline vehicle) plus oral placebo syrup (quantity matching oxycodone syrup volume), or 3) 20ml i.v. saline placebo plus oral placebo syrup (quantity matching oxycodone syrup volume). Thermal pain testing utilizes a Medoc TSAII NeuroSensory Analyzer. This equipment is used to assess heat pain threshold and tolerance using an ascending method of limits protocol.
Primary outcome measures
Mean change in McGill Pain Questionnaire-2 (MPQ-2) ratings of low back pain from the placebo to oxycodone condition
Time frame: Across 2 laboratory assessment days (an expected average of 15 day period)
Mean within participant changes in McGill Pain Questionnaire-2 (MPQ-2) ratings of low back pain from the placebo to oxycodone condition (across 2 testing days). The MPQ-2 score ranges from 0-10 where 0 represents no pain and 10 represents most intense pain. Positive change values indicate decreased pain responsiveness post intervention.
Mean DELTA Drug Liking subscale scores in the oxycodone condition
Time frame: One 1 laboratory assessment day
Mean DELTA Drug Liking subscale scores in the oxycodone condition. The DELTA Drug Liking subscale consists of a single item asking about overall perceived drug liking. The 1-5 scale is anchored with 1 representing dislike a lot and 5 representing like a lot.
Composite measure of changes in MPQ-2 ratings of low back pain from the placebo to naloxone condition (standardized) plus plasma levels of endocannabinoids (standardized)
Time frame: Across 2 laboratory assessment days (an expected average of 15 day period)
Composite measure of changes in MPQ-2 ratings of low back pain from the placebo to naloxone condition (standardized) plus plasma levels of endocannabinoids (standardized). More negative standardized values will indicate low levels of endogenous pain inhibition and more positive levels will indicate high levels of endogenous pain inhibition.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Intact cognitive status and ability to provide informed consent
- Ability to read and write in English sufficiently to understand and complete study questionnaires (which are only validated in English)
- Age 18 or older And
- Presence of persistent daily low back pain of at least three months duration and of at least a 3/10 in average intensity
Exclusion criteria
- History of renal or hepatic dysfunction
- Reports of current or past alcohol or substance abuse or treatment for such condition
- A reported history of PTSD, psychotic, or bipolar disorders
- Chronic pain due to malignancy (e.g., cancer) or autoimmune disorders (e.g., rheumatoid arthritis, lupus)
- Reports of recent benzodiazepine use (confirmed via rapid urine screening prior to each lab session)
- Any medical conditions (e.g., significant cardiovascular disease) that the study physician feels would contraindicate participation in the lab stressors
- Reported daily opiate use within the past 6 months, or use of any opioid analgesic medications within 3 days of study participation (confirmed through rapid urine screening prior to each lab session)
- Pregnancy (females only, to avoid fetal drug exposure - pregnancy tests conducted prior to each lab session to confirm eligibility)
- Prior allergic reaction/intolerance to oxycodone or its analogs
Where
- Nashville, Tennessee
Collaborators
National Institute on Drug Abuse (NIDA)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Oct 21, 2025 · Source of record for eligibility and locations