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Completed

NCT Number: NCT04105998

Effects of Intramuscular (IM) Oxytocin on Pupil Diameter and Heart Rate Variability (HRV)

The goal of this study is to test the effects of oxytocin on heart rate variability and pupil diameter, both of which have subtle effects on the activity rate of the autonomic nervous system.

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Key information

Conditions

Chronic Pain Due to Injury

Age range

18 year–66 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Wake Forest Baptist Health

Winston-Salem, North Carolina, 27157, United States

About this study

This protocol focuses on two measures of autonomic control to quantify central actions of oxytocin. First, the study team proposes to examine the influence of oxytocin on heart rate variability with focus on its effect on high frequency variability, most commonly ascribed to parasympathetic nervous system activity acting to brake sympathetic tone. Intranasal oxytocin has been demonstrated to have a large effect size on this measure which can be repeated at frequent intervals. As a secondary assessment of parasympathetic activity, the study team will measure low frequency fluctuation in pupil diameter, termed hippus, which also reflects parasympathetic nervous system activity. This outcome measure can be assessed in 3 seconds using equipment currently being used under Institutional Review Board (IRB) approved protocols.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Male or female > 18 and < 66 years of age,
  • Body Mass Index (BMI) <40
  • Generally in good health as determined by the Principal Investigator based on prior medical history
  • Normal blood pressure and resting heart rate without medication

Exclusion criteria

  • 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
  • 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.
  • Neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis.
  • Previous eye surgery, eye medications, cataracts

Treatment and study plan

Oxytocin

Drug

Oxytocin 10 IU

Other names: Pitocin

Placebo

Drug

Placebo

Other names: saline

Primary outcomes

  1. Fluctuation in Pupil Diameter (Hippus) -Pre Drug Administration

    Time frame: From 20 minutes before until study drug injection

    Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter in the .1-2 Hz range, termed hippus. Pupil measurements will be made for 20 seconds every 5 minutes for 20 minutes. The Fast Fourier Transform (FFT) essentially takes what looks like a random, noisy signal and distills it into a combination of many sine waves, each with different frequencies and different sizes (think ocean waves, which has the big wave we see and the small up and down wavelets on the top of the water). The primary outcome measure is the size of the largest wave in the frequency range above in this FFT analysis. Its dimensions are milliseconds^2.

  2. Fluctuation in Pupil Diameter (Hippus) -Post Drug Administration

    Time frame: For 90 minutes after study drug administration

    Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter in the .1-2 Hz range, termed hippus. Pupil measurements will be made for 20 seconds every 5 minutes until 90 minutes after study drug administration. The Fast Fourier Transform (FFT) essentially takes what looks like a random, noisy signal and distills it into a combination of many sine waves, each with different frequencies and different sizes (think ocean waves, which has the big wave we see and the small up and down wavelets on the top of the water). The primary outcome measure is the size of the largest wave in the frequency range above in this FFT analysis. Its dimensions are milliseconds^2.

  3. Fluctuation in Pupil Diameter (Hippus) -Post Drug Administration

    Time frame: For 120 minutes after study drug administration

    Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter in the .1-2 Hz range, termed hippus. Pupil measurements will be made for 20 seconds every 5 minutes until 120 minutes after study drug administration. The Fast Fourier Transform (FFT) essentially takes what looks like a random, noisy signal and distills it into a combination of many sine waves, each with different frequencies and different sizes (think ocean waves, which has the big wave we see and the small up and down wavelets on the top of the water). The primary outcome measure is the size of the largest wave in the frequency range above in this FFT analysis. Its dimensions are milliseconds^2.

  4. Heart Rate Variability in the High Frequency Range

    Time frame: From 20 minutes before until study drug injection

    Magnitude of peak power in the 0.12-0.40 Hz frequency range of the Fast Fourier Transform of heart rate. The Fast Fourier Transform (FFT) essentially takes what looks like a random, noisy signal and distills it into a combination of many sine waves, each with different frequencies and different sizes (think ocean waves, which has the big wave we see and the small up and down wavelets on the top of the water). The primary outcome measure is the size of the largest wave in the frequency range above in this FFT analysis. Its dimensions are milliseconds^2.

  5. Heart Rate Variability in the High Frequency Range

    Time frame: For 90 minutes after study drug administration

    Magnitude of peak power in the 0.12-0.40 Hz frequency range of the Fast Fourier Transform of heart rate. The Fast Fourier Transform (FFT) essentially takes what looks like a random, noisy signal and distills it into a combination of many sine waves, each with different frequencies and different sizes (think ocean waves, which has the big wave we see and the small up and down wavelets on the top of the water). The primary outcome measure is the size of the largest wave in the frequency range above in this FFT analysis. Its dimensions are milliseconds^2.

  6. Heart Rate Variability in the High Frequency Range

    Time frame: For 120 minutes after study drug administration

    Magnitude of peak power in the 0.12-0.40 Hz frequency range of the Fast Fourier Transform of heart rate. The Fast Fourier Transform (FFT) essentially takes what looks like a random, noisy signal and distills it into a combination of many sine waves, each with different frequencies and different sizes (think ocean waves, which has the big wave we see and the small up and down wavelets on the top of the water). The primary outcome measure is the size of the largest wave in the frequency range above in this FFT analysis. Its dimensions are milliseconds^2.

Sponsors and collaborators

Lead sponsor

Wake Forest University Health Sciences

Other

Registry information

Official study title

Effects of Intramuscular Oxytocin on Pupil Diameter and Heart Rate Variability

Important dates

Study start
2019
Primary completion
2021
Study completion
2021
First posted
Sep 26, 2019
Registry last updated
Nov 10, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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