Trial · NCT04473950
The Effect of Chronic Pain on Delay Discounting in Methadone Patients
NCT04473950, Phase 1, Terminated, University of California, San Francisco; results first posted 2025-03-26
3 sourcestrials-2026-11-12-0.5.0
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ConductScience Library. The Effect of Chronic Pain on Delay Discounting in Methadone Patients. Trials, record NCT04473950. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT04473950
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Trial
As registered on ClinicalTrials.gov, in the graph's capture of the registry.
- Title
- The Effect of Chronic Pain on Delay Discounting in Methadone Patients
- NCT number
- NCT04473950
- Status
- Terminated
- Phases
- Phase 1
- Enrollment
- 10 participants, actual
- Lead sponsor
- University of California, San Francisco
- Conditions
- Opioid-use Disorder, Chronic Pain Syndrome
- Interventions
- Naloxone Hydrochloride, Placebo
- First posted
- 2020-07-16
- Last updated
- 2025-03-26
- Results first posted
- 2025-03-26
- Limitations and caveats
COVID-19 Public Health Emergency caused almost complete stoppage of research activities for over half of the grant time. We only had 10% of the proposed number of completers. Therefore, the decision was made to halt the study.
Source ClinicalTrials.gov
Registered outcomes5
Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.
| List | Outcome | Time frame | Description |
|---|---|---|---|
| Primary | Delay Discounting of Money Rate (k) | k will be calculated from the same series of discounting questions that will be asked once each session at approximately 30 minutes after study medication administration. | Delay discounting is the relative preference for smaller sooner over larger later rewards, an aspect of impulsivity. Most individuals would prefer an immediate $100 over $100 delayed by 1 year. However, when faced with the choice between receiving $95 now versus $100 in 1 year, preferences for the delayed reward may increase. By assessing such choices across multiple delays, delay discounting quantifies the devaluation of rewards over time, which allows for an index of overall discounting rate (k). Delay Discounting of money rate has no units and values can go from 0-infinity. A larger discount rate indicates that a future reward is devalued more, and is associated with more impulsive behavior. |
| Secondary | Study Session Peak Pain Visual Analog Scale (VAS) | Peak Pain VAS will be the highest rating during each 2 hour study session. | Current pain level rated on 0-100 VAS. This is the validated pain scale typically used by clinicians in an outpatient or inpatient clinical visit to represent current level of pain. Higher ratings indicate worse pain severity. |
| Secondary | Peak Clinical Opiate Withdrawal Scale (COWS) Rating | Peak COWS rating will be the highest rating during each 2 hour study session. | The COWS is an 11-item validated clinician administered scale that quantifies level of opioid withdrawal. The range of scores is 0-48, with higher scores indicating greater withdrawal severity. The peak COWS rating will be the highest measurement in the session after study drug administration. |
| Secondary | Peak Subjective Opiate Withdrawal Scale (SOWS) Rating | Peak SOWS rating will be the highest rating during each 2 hour study session. | The SOWS is a 16 item validated self-administered scale for grading opioid withdrawal symptoms. The range of scores is 0-64, with higher scores indicating greater withdrawal severity. The peak SOWS rating will be the highest measurement in the session after study drug administration. |
| Secondary | Peak Increase From Baseline Pupil Diameter | Peak increase from baseline pupil diameter will be the largest increase from baseline pupil diameter measured during each 2 hour study session. | Pupil diameter (mm) will be measured via digital pupillometer in standard room lighting at baseline and then throughout the study session after study drug administration. The peak increase from baseline value will be the largest increase from baseline pupil diameter measured after study drug administration. |
Source ClinicalTrials.gov
Outcomes5
Each outcome the trial posted results for, in ClinicalTrials.gov's words.
| Type | Outcome | Time frame | Population | Units | Measured as |
|---|---|---|---|---|---|
| PRIMARY | Delay Discounting of Money Rate (k) | k will be calculated from the same series of discounting questions that will be asked once each session at approximately 30 minutes after study medication administration. | k-value | MEAN | |
| SECONDARY | Study Session Peak Pain Visual Analog Scale (VAS) | Peak Pain VAS will be the highest rating during each 2 hour study session. | There was missing data for one participant with chronic pain in the placebo session. | score on a scale | MEAN |
| SECONDARY | Peak Clinical Opiate Withdrawal Scale (COWS) Rating | Peak COWS rating will be the highest rating during each 2 hour study session. | score on a scale | MEAN | |
| SECONDARY | Peak Subjective Opiate Withdrawal Scale (SOWS) Rating | Peak SOWS rating will be the highest rating during each 2 hour study session. | score on a scale | MEAN | |
| SECONDARY | Peak Increase From Baseline Pupil Diameter | Peak increase from baseline pupil diameter will be the largest increase from baseline pupil diameter measured during each 2 hour study session. | millimeters | MEAN |
Source ClinicalTrials.gov
Results by group20
Each measurement the trial posted, group by group, in the words and numbers it posted.
| Outcome | Group | Category | Value | Spread | Units |
|---|---|---|---|---|---|
| Delay Discounting of Money Rate (k) | Pain Group | Naloxone Session | -1.65 | Standard Deviation 1.17 | k-value |
| Delay Discounting of Money Rate (k) | No Pain Group | Naloxone Session | -2.16 | Standard Deviation 0.92 | k-value |
| Delay Discounting of Money Rate (k) | Pain Group | Placebo Session | -1.91 | Standard Deviation 0.56 | k-value |
| Delay Discounting of Money Rate (k) | No Pain Group | Placebo Session | -2.11 | Standard Deviation 1.11 | k-value |
| Study Session Peak Pain Visual Analog Scale (VAS) | Pain Group | Placebo | 25.2 | Standard Deviation 22.9 | score on a scale |
| Study Session Peak Pain Visual Analog Scale (VAS) | No Pain Group | Placebo | 0 | Standard Deviation 0 | score on a scale |
| Study Session Peak Pain Visual Analog Scale (VAS) | Pain Group | Naloxone | 28.2 | Standard Deviation 25.4 | score on a scale |
| Study Session Peak Pain Visual Analog Scale (VAS) | No Pain Group | Naloxone | 0.25 | Standard Deviation 0.5 | score on a scale |
| Peak Clinical Opiate Withdrawal Scale (COWS) Rating | Pain Group | Placebo | 1.8 | Standard Deviation 0.98 | score on a scale |
| Peak Clinical Opiate Withdrawal Scale (COWS) Rating | No Pain Group | Placebo | 2.75 | Standard Deviation 0.5 | score on a scale |
1 to 10 of 20Source ClinicalTrials.gov
See all 20 results by groupParticipant flow10
How many started, completed or left each group, period by period.
| Period | Milestone | Group | Participants | Units counted |
|---|---|---|---|---|
| Overall Study | STARTED | Pain Group | 6 | |
| Overall Study | STARTED | No Pain Group | 4 | |
| Overall Study | Naloxone | Pain Group | 6 | |
| Overall Study | Naloxone | No Pain Group | 4 | |
| Overall Study | Placebo | Pain Group | 6 | |
| Overall Study | Placebo | No Pain Group | 4 | |
| Overall Study | COMPLETED | Pain Group | 6 | |
| Overall Study | COMPLETED | No Pain Group | 4 | |
| Overall Study | NOT COMPLETED | Pain Group | 0 | |
| Overall Study | NOT COMPLETED | No Pain Group | 0 |
Source ClinicalTrials.gov
Adverse events20
Each adverse event the trial posted, group by group: the participants affected out of those at risk.
| Type | Event | Organ system | Group | Affected | At risk | Events |
|---|---|---|---|---|---|---|
| other | Dizziness | Nervous system disorders | Pain Group, Placebo Session | 0 | 6 | 0 |
| other | Dizziness | Nervous system disorders | Pain Group, Naloxone Session | 1 | 6 | 1 |
| other | Dizziness | Nervous system disorders | No Pain Group, Placebo Session | 0 | 4 | 0 |
| other | Dizziness | Nervous system disorders | No Pain Group, Naloxone Session | 0 | 4 | 0 |
| other | Tunnel Vision | Eye disorders | Pain Group, Placebo Session | 0 | 6 | 0 |
| other | Tunnel Vision | Eye disorders | Pain Group, Naloxone Session | 1 | 6 | 1 |
| other | Tunnel Vision | Eye disorders | No Pain Group, Placebo Session | 0 | 4 | 0 |
| other | Tunnel Vision | Eye disorders | No Pain Group, Naloxone Session | 0 | 4 | 0 |
| other | Paranoia | Nervous system disorders | Pain Group, Placebo Session | 0 | 6 | 0 |
| other | Paranoia | Nervous system disorders | Pain Group, Naloxone Session | 1 | 6 | 1 |
1 to 10 of 20Source ClinicalTrials.gov
See all 20 adverse eventsAdverse event totals12
The totals the trial posted for each group.
| Total | Group | Affected | At risk |
|---|---|---|---|
| Total, all-cause mortality | Pain Group, Placebo Session | 0 | 6 |
| Total, all-cause mortality | Pain Group, Naloxone Session | 0 | 6 |
| Total, all-cause mortality | No Pain Group, Placebo Session | 0 | 4 |
| Total, all-cause mortality | No Pain Group, Naloxone Session | 0 | 4 |
| Total, other adverse events | Pain Group, Placebo Session | 1 | 6 |
| Total, other adverse events | Pain Group, Naloxone Session | 2 | 6 |
| Total, other adverse events | No Pain Group, Placebo Session | 1 | 4 |
| Total, other adverse events | No Pain Group, Naloxone Session | 0 | 4 |
| Total, serious adverse events | Pain Group, Placebo Session | 0 | 6 |
| Total, serious adverse events | Pain Group, Naloxone Session | 0 | 6 |
1 to 10 of 12Source ClinicalTrials.gov
See all 12 adverse event totalsPapers0
The papers the trial lists on ClinicalTrials.gov.
None in this release.
Grants1
The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.
| Project | Title | Principal investigators | Organization | Funder | Fiscal years |
|---|---|---|---|---|---|
| R21DA047520 | The Effect of Chronic Pain on Delay Discounting in Methadone Patients | TOMPKINS, DAVID ANDREW | UNIVERSITY OF CALIFORNIA, SAN FRANCISCO | NATIONAL INSTITUTE ON DRUG ABUSE | 2019 to 2020 |
Source NIH RePORTER
Trial comparisons0
Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.
None in this release.
Tests1
The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.
| Test | Named as |
|---|---|
| Delay Discounting | Primary outcome |
Source ConductCognition
Data dates
The day each source was copied for this release.
Sources 3
- ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
- ClinicalTrials.govNo license stated
- NIH RePORTER's clinical studies and project filesPublic domain
Each source's terms
- ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
- ClinicalTrials.govnone stated
- NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)
ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.
For software
Read this trial from software.
The record and each of its lists are JSON, twenty rows a page. No key.
GET https://conductscience.org/api/trials/v1/NCT04473950
GET https://conductscience.org/api/trials/v1/NCT04473950/registered