Dose Ranging Study of Intravenous Oxytocin for Analgesia to Heat Pain
Condition: Healthy Volunteer Study
Study type: Interventional
Phase: Phase 2

Summary: 
      This is a study of participants that will receive intravenous (IV) infusions of oxytocin
      (naturally occurring hormone that is made by the brain).

      In this study healthy participants will be recruited for the study. There will be 3 study
      related visits: 1) screening and informed consent 2) study medication infusions and thermal
      heat testing 3) study medication infusions and thermal heat testing. During study visits 2
      and 3 an IV catheter will be placed and a dose of oxytocin or placebo (inactive solution)
      will be given over a 10 minute period; 1 hour after the first infusion, a second 10 minute
      infusion of oxytocin will be administered.

      Investigators will perform some tests to evaluate how oxytocin changes perceptions of the
      skin. Investigators will study a painful perception by placing a probe on the skin of the
      side of lower leg and heating it up to 113-117 degrees Fahrenheit (F) (45-47 degrees Celsius
      (C)) for 5 minutes. Each participant will score any pain that is experienced on a 0 to 10
      scale for each minute during the heating period. Most people find that pain rises during the
      5 minutes, but remains mild; usually less than 5 on the 0 to 10 pain scale. The temperature
      of the 5 minute heating will be determined according to the participants pain rating during
      the screening visit.

      The primary objective of the study is to determine the dose response of IV oxytocin for
      analgesia (pain relief) to experimental heat pain.
    

Detailed description: 
      Equal numbers of adult men and women; ages 18-75 will be recruited. Participants will report
      to the research unit for three visits, 1) screening and informed consent 2) study medication
      infusions and thermal heat testing 3) study medication infusions and thermal heat testing
      separated by at least 72 hours.

      For study infusion visits, study participants will come to the Clinical Research Unit and one
      intravenous (IV) catheter will be inserted in the forearm for oxytocin infusions.
      Participants in this study will receive a dose of oxytocin or placebo at a steady rate for 10
      minutes; one hour later, a second dose of oxytocin will be administered during one visit.
      During the second study infusion visit, a lower dose of oxytocin will be given by a 10-minute
      IV infusion and one hour later a second infusion of oxytocin at a higher dose will be given.
      The order of infusions will be randomized and double-blinded. As a result, each participant
      will receive oxytocin doses of 0, 0.3, 1.3, and 7 micrograms(µg) in this double blind design.
    

Intervention name(s): saline (placebo) then oxytocin 1.3 micrograms; Experimental: oxytocin 0.3 micrograms then oxytocin 7 micrograms
Intervention type(s): Drug; Drug
Intervention description(s): 10 minute IV infusion of saline followed by a 10 minute infusion of oxytocin 1.3 micrograms; 10 minute IV infusion of oxytocin 0.3 micrograms followed by a 10 minute infusion of oxytocin 7 micrograms
Other intervention name(s): Pitocin; Pitocin
Intervention MeSH terms: Oxytocin
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Each participant will receive 2 IV infusions separated by 1 hour
saline (placebo) then oxytocin 1.3 micrograms
oxytocin 0.3 micrograms then oxytocin 7 micrograms
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Basic Science