Oxytocin and Pupillary Hippus in Chronic Pain and Osteoarthritis

This study is looking at how oxytocin (Pitocin®), a natural hormone given as an injection, affects your body's "rest and digest" system, specifically in people with chronic pain from knee osteoarthritis or healthy volunteers. Researchers want to see if oxytocin changes how your pupils fluctuate (called "hippus"), which can tell them about your central nervous system activity. You would receive either oxytocin or a placebo (an inactive injection) on two separate visits. The main goal is to measure these pupil changes before and up to 180 minutes after the injection. This study is currently recruiting 38 participants aged 18 to 75 years old.

Study design
This is a randomized, double-blind study involving 38 participants. You would receive both oxytocin and a placebo injection on different visits.
What's involved
You would visit the Pain Clinical Research Unit on two separate occasions. On each visit, you'll receive an injection and have your pupil diameter measured for up to 180 minutes.
Compensation
Not stated in the trial record.
Follow-up
Your pupil diameter will be measured for up to 180 minutes after each injection, after which you will be discharged.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT04427709

Generate and Test the Reliability of a PD Model of OXT on Pupillary Hippus as a Measure of CNS Activity

Terminated
PHASE2Ages 18–75InterventionalBasic science
Wake Forest University Health Sciences
~4 participants
Updated 2026-08-28 on ClinicalTrials.gov
What's tested:OxytocinPlacebo

At a glance

Recruiting sites
0 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Fluctuation in Pupil Diameter (Hippus) -Pre drug administration
Measured over Baseline before study drug administration
+1 more outcome measured
Chronic Pain
Osteoarthritis, Knee

NCT04427709

Where you'd take part

This study runs at 1 site. They're the same protocol — you choose where, and that choice sets who your contact draft is addressed to.

  • Wake Forest Baptist Health

    Winston-Salem, North Carolinano site contact published

Sites open and close at different times, so the status above is per site — it can differ from the study's overall status.

  • James C Eisenach, MD · PRINCIPAL_INVESTIGATOR · Wake Forest University Health Sciences

This trial hasn't published a contact. View it on ClinicalTrials.gov

  • Fluctuation in Pupil Diameter (Hippus) -Pre drug administrationBaseline 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 administrationup 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.