PK Sampling After IV Oxytocin and Effects on Sensory Function in Healthy Volunteers
Condition: Chronic Pain
MeSH terms: Chronic Pain
Intervention: Oxytocin
Intervention description: Single IV administration of oxytocin
Intervention MeSH terms: Oxytocin
Phase: Phase 4
Study type: Interventional
Primary purpose: Basic Science
Intervention model: Single Group Assignment
Intervention model description: Single intravenous administration of oxytocin (Pitocin®), 10 IU
Masking: None (Open Label)
Enrollment: 11.0
Sex: All
Minimum age: 18 Years
Maximum age: 60 Years
Healthy volunteers: Accepts Healthy Volunteers

Summary:

      The primary goal of this protocol is to model change in oxytocin concentrations in plasma
      after intravenous (IV) administration. Additional measurements will be performed on sensory
      function that could be influenced by oxytocin during later time periods when blood samples
      are widely separated by time. This protocol will describe the pharmacokinetics (PK) of
      intravenous oxytocin in healthy adult men and adult,non-pregnant women. PK samples will be
      obtained after an injection of intravenous oxytocin 10 IU over 60 seconds.

      Blood will be drawn for the PK samples prior to the oxytocin administration and then 11 times
      after administration.

      There are two additional measures which will assess two different aspects of sensory
      function.

      MEASURE 1: Light Touch Frequency Threshold In order to determine the highest frequency that
      specific nerve fibers can respond to, a simple device that produces an oscillatory /
      vibratory stimulus will be used on the hand. The subject places fingertips, palm, and palm
      side of the wrist sequentially and the device is set to slowly decrease the frequency of
      vibration from 1 kHz until the subject first perceives this. This is repeated three times at
      each site and takes less than 5 minutes in total. This will be performed before the oxytocin
      administration and 6 times after the administration of IV Oxytocin.

      MEASURE 2: Sustained Heat The surface of the skin of the forearm or leg is heated to 113°F
      using a computer controlled thermode for a period of 5 minutes. This will be done before the
      IV Oxytocin and 4 times after the administration. A set of random thermal temperatures
      (98°F-122°F) will also be applied to the skin of the leg or forearm before the IV Oxytocin
      administration and 4 times after administration of IV Oxytocin.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Male or female > 18 and < 60 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 I or II

          -  Normal blood pressure (systolic 90-140 mmHg; diastolic 50-90 mmHg) resting heart rate
             45-100 beats per minute) without medication

          -  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

        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 (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.