Chronic PainPhase 2NCT04427709
Generate and Test the Reliability of a PD Model of OXT on Pupillary Hippus as a Measure of CNS Activity
A Phase 2 study testing Oxytocin in people with Chronic Pain and Osteoarthritis, Knee, run by Wake Forest University Health Sciences at 1 site in United States.
Trial summary
The purpose of this research is to evaluate the effects of oxytocin (naturally occurring hormone) given by an intramuscular (IM; into the muscle) injection, has on your parasympathetic nervous system. Read more about this study
- Who is it for?
- Ages 18 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Chronic Pain, Osteoarthritis, Knee
- What is being tested?
- Oxytocin
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 4 participants
- Where
- 1 siteUnited States
- Study dates
- 30 Nov 2020to 1 Aug 2026
- Phase
- Phase 2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Male or female > 18 and < 75 years of age, Body Mass Index (BMI) <40.
- Generally in good health as determined by the Principal Investigator based on prior medical history, American Society of Anesthesiologists physical status 1, 2, or 3.
- For healthy volunteers, normal blood pressure (systolic 90-140 mmHg; diastolic 50-90 mmHg) resting heart rate 45-100 beats per minute) without medication. For knee arthritis subjects, normal blood pressure or, for those with hypertension, pressure controlled with anti-hypertensives and with a resting heart rate 45-100 beats per minute.
- Female subjects of child-bearing potential and those < 1 year post-menopausal, must be practicing highly effective methods of birth control such as hormonal methods (e.g., combined oral, implantable, injectable, or transdermal contraceptives), double barrier methods (e.g., condoms, sponge, diaphragm, or vaginal ring plus spermicidal jellies or cream), or total abstinence from heterosexual intercourse for a minimum of 1 full cycle before study drug administration.
Who cannot join
- Hypersensitivity, allergy, or significant reaction to any ingredient of Pitocin®
- Any disease, diagnosis, or condition (medical or surgical) that, in the opinion of the Principal Investigator, would place the subject at increased risk (active gynecologic disease in which increased tone would be detrimental e.g., uterine fibroids with ongoing bleeding), compromise the subject's compliance with study procedures, or compromise the quality of the data
- Women who are pregnant (positive result for serum pregnancy test at screening visit), women who are currently nursing or lactating, women that have been pregnant within 2 years
- Subjects with neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis.
- Subjects with eye pathology, eye surgery, or taking topical eye medications, or any disease process that would cause motor tremors or excessive eye movements.
Trial locations and contacts
1 site in 1 country.
United States1 site
Wake Forest Baptist Health
Winston-Salem, North Carolina, 27157
About this study
Official title: Generate and Test the Reliability of a Pharmacodynamic Model of Oxytocin on Pupillary Hippus as a Measure of Central Nervous System Activity
The purpose of this research is to evaluate the effects of oxytocin (naturally occurring hormone) given by an intramuscular (IM; into the muscle) injection, has on your parasympathetic nervous system. The parasympathetic nervous system is the part of the involuntary nervous system that is sometimes called the "rest and digest" system; the parasympathetic system conserves energy as it slightly slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract.
Read the detailed description
This is a single site study at Wake Forest School of Medicine. Healthy volunteers and patients with advanced knee arthritis being seen in the Orthopedic Clinic in consultation for potential total knee arthroplasty will be recruited after their doctor visit if the decision is made not to perform surgery at this time.
Study participants will come to the Pain Clinical Research Unit on 2 occasions. On these visits, they will receive an intramuscular (i.m.) injection of placebo or oxytocin, 25 micrograms (μg) (Pitocin®), obtained from the research pharmacy. The order in this cross-over study will be randomized and double blind, and the studies separated by at least 48 hours. Every 2.5 minutes beginning 20 minutes before injection and until 180 minutes after injection oscillation in pupil diameter at low frequency (hippus) will be obtained using an infrared pupilometer, in which they focus on a central point of gaze for 20 seconds. Hippus, a measure of parasympathetic output to the pupil and affected by central actions of oxytocin as described in preliminary data, will be calculated as the magnitude of power in the 0-0.25 Hertz (Hz) bin of the spectral analysis of pupil diameter, after removing blink and saccade artifacts. After 180 minutes the study participant will be discharged from the Pain Clinical Research Unit.
- Conditions
- Chronic Pain, Osteoarthritis, Knee
- Being tested
- Oxytocin, Placebo
- Medical subject headings
- Chronic Pain, Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
OxytocinDrug
Also called Pitocin
Intramuscular injection of Oxytocin (Pitocin®)
PlaceboDrug
Intramuscular placebo injection
| Study group | Role | What they receive |
|---|---|---|
| Oxytocin First, then Placebo | Other | Subjects in this arm will receive Intramuscular injection of Oxytocin (Pitocin®) first then placebo injection. Receives: Drug: Oxytocin; Drug: Placebo |
| Placebo, Then Oxytocin | Other | Subjects in this arm will receive Intramuscular placebo injection first then oxytocin injection Receives: Drug: Oxytocin; Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fluctuation in Pupil Diameter (Hippus) -Pre drug administration
Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter.
One measure of coefficient of variation at each time period. It is calculated by the amount of variability in a window of time.
Every 2.5 minutes beginning 20 minutes before the intramuscular injection of placebo or oxytocin, 25 micrograms.
Measured: Baseline before study drug administration
Fluctuation in Pupil Diameter (Hippus) -Post drug administration
Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter.
One measure of coefficient of variation at each time period. It is calculated by the amount of variability in a window of time.
Every 2.5 minutes for 180 after intramuscular injection of placebo or oxytocin, 25 micrograms.
Measured: up to 180 minutes after study drug administration
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2020
- Study start30 Nov 2020
- Primary completion1 Aug 2026
- Study completion1 Aug 2026
Why it stopped: This study was initiated for preliminary data to support NIH grant submission. The study was maintained active in anticipation of returning to the protocol. Due to funding and current NIH grant work this study could not be completed.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Chronic PainStudies of the same condition, open and under way.
- More trials run by Wake Forest University Health SciencesThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Randomized, double blind, crossover study. Each participant will receive Oxytocin 25 micrograms and placebo via intramuscular injection
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 4 participants (actual)
Sponsor and investigators
- Lead sponsor
- Wake Forest University Health Sciences
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- James C Eisenach, MD, Principal investigator, Wake Forest University Health Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04427709
- Sponsor's protocol ID
- IRB00066475
- Other IDs
- 5P01NS119159-02
- Status last verified
- Dec 2025
- First submitted
- 9 Jun 2020
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Generate and Test the Reliability of a Pharmacodynamic Model of Oxytocin on Pupillary Hippus as a Measure of Central Nervous System Activity
- ClinicalTrials.gov ID
- NCT04427709
- Acronym / sponsor ID
- IRB00066475
- Conditions
- Chronic Pain, Osteoarthritis, Knee
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: This study was initiated for preliminary data to support NIH grant submission. The study was maintained active in anticipation of returning to the protocol. Due to funding and current NIH grant work this study could not be completed.
- Enrolment
- 4 participants (actual)
- Lead sponsor
- Wake Forest University Health SciencesUniversity, hospital or other
- Collaborators
- National Institute of Neurological Disorders and Stroke (NINDS)
- Study start
- 30 Nov 2020 (actual)
- Primary completion
- 1 Aug 2026 (actual)
- Study completion
- 1 Aug 2026 (actual)
- First posted
- 11 Jun 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this research is to evaluate the effects of oxytocin (naturally occurring hormone) given by an intramuscular (IM; into the muscle) injection, has on your parasympathetic nervous system. The parasympathetic nervous system is the part of the involuntary nervous system that is sometimes called the "rest and digest" system; the parasympathetic system conserves energy as it slightly slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract.
Detailed description
This is a single site study at Wake Forest School of Medicine. Healthy volunteers and patients with advanced knee arthritis being seen in the Orthopedic Clinic in consultation for potential total knee arthroplasty will be recruited after their doctor visit if the decision is made not to perform surgery at this time.
Study participants will come to the Pain Clinical Research Unit on 2 occasions. On these visits, they will receive an intramuscular (i.m.) injection of placebo or oxytocin, 25 micrograms (μg) (Pitocin®), obtained from the research pharmacy. The order in this cross-over study will be randomized and double blind, and the studies separated by at least 48 hours. Every 2.5 minutes beginning 20 minutes before injection and until 180 minutes after injection oscillation in pupil diameter at low frequency (hippus) will be obtained using an infrared pupilometer, in which they focus on a central point of gaze for 20 seconds. Hippus, a measure of parasympathetic output to the pupil and affected by central actions of oxytocin as described in preliminary data, will be calculated as the magnitude of power in the 0-0.25 Hertz (Hz) bin of the spectral analysis of pupil diameter, after removing blink and saccade artifacts. After 180 minutes the study participant will be discharged from the Pain Clinical Research Unit.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized, double blind, crossover study. Each participant will receive Oxytocin 25 micrograms and placebo via intramuscular injection
| Arm | Type | Receives |
|---|---|---|
| Oxytocin First, then Placebo | Other | Drug: Oxytocin, Drug: PlaceboSubjects in this arm will receive Intramuscular injection of Oxytocin (Pitocin®) first then placebo injection. |
| Placebo, Then Oxytocin | Other | Drug: Oxytocin, Drug: PlaceboSubjects in this arm will receive Intramuscular placebo injection first then oxytocin injection |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Male or female > 18 and < 75 years of age, Body Mass Index (BMI) <40.
- Generally in good health as determined by the Principal Investigator based on prior medical history, American Society of Anesthesiologists physical status 1, 2, or 3.
- For healthy volunteers, normal blood pressure (systolic 90-140 mmHg; diastolic 50-90 mmHg) resting heart rate 45-100 beats per minute) without medication. For knee arthritis subjects, normal blood pressure or, for those with hypertension, pressure controlled with anti-hypertensives and with a resting heart rate 45-100 beats per minute.
- Female subjects of child-bearing potential and those < 1 year post-menopausal, must be practicing highly effective methods of birth control such as hormonal methods (e.g., combined oral, implantable, injectable, or transdermal contraceptives), double barrier methods (e.g., condoms, sponge, diaphragm, or vaginal ring plus spermicidal jellies or cream), or total abstinence from heterosexual intercourse for a minimum of 1 full cycle before study drug administration.
Key exclusion criteria (5 listed)
- Hypersensitivity, allergy, or significant reaction to any ingredient of Pitocin®
- Any disease, diagnosis, or condition (medical or surgical) that, in the opinion of the Principal Investigator, would place the subject at increased risk (active gynecologic disease in which increased tone would be detrimental e.g., uterine fibroids with ongoing bleeding), compromise the subject's compliance with study procedures, or compromise the quality of the data
- Women who are pregnant (positive result for serum pregnancy test at screening visit), women who are currently nursing or lactating, women that have been pregnant within 2 years
- Subjects with neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis.
- Subjects with eye pathology, eye surgery, or taking topical eye medications, or any disease process that would cause motor tremors or excessive eye movements.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| OxytocinAlso: PitocinIntramuscular injection of Oxytocin (Pitocin®) | Drug | Oxytocin First, then Placebo, Placebo, Then Oxytocin |
| PlaceboIntramuscular placebo injection | Drug | Oxytocin First, then Placebo, Placebo, Then Oxytocin |
Primary outcome
Fluctuation in Pupil Diameter (Hippus) -Pre drug administration
Time frame: Baseline before study drug administration
Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter. One measure of coefficient of variation at each time period. It is calculated by the amount of variability in a window of time. Every 2.5 minutes beginning 20 minutes before the intramuscular injection of placebo or oxytocin, 25 micrograms.
Fluctuation in Pupil Diameter (Hippus) -Post drug administration
Time frame: up to 180 minutes after study drug administration
Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter. One measure of coefficient of variation at each time period. It is calculated by the amount of variability in a window of time. Every 2.5 minutes for 180 after intramuscular injection of placebo or oxytocin, 25 micrograms.
Results and safety
The study was stopped early (reason given: This study was initiated for preliminary data to support NIH grant submission. The study was maintained active in anticipation of returning to the protocol. Due to funding and current NIH grant work this study could not be completed.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
James C Eisenach, MD principal investigator
Wake Forest University Health Sciences
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Oxytocin in people with Chronic Pain and Osteoarthritis, Knee, run by Wake Forest University Health Sciences at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study was stopped early (reason given: This study was initiated for preliminary data to support NIH grant submission. The study was maintained active in anticipation of returning to the protocol. Due to funding and current NIH grant work this study could not be completed.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fluctuation in Pupil Diameter (Hippus) -Pre drug administration (time frame: Baseline before study drug administration). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Oct 2026.