The Effects of Prazosin on Dopamine in Healthy Humans: A PET Pilot Study
Condition: Healthy
Intervention: Prazosin Hydrochloride
Intervention description: Gradual upward titration to 15mg/day for approximately three weeks.
Intervention MeSH terms: Prazosin
Phase: Phase 1
Study type: Interventional
Primary purpose: Basic Science
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 20.0
Sex: All
Minimum age: 19 Years
Maximum age: 45 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: prazosin; dopamine; healthy; Positron Emission Tomography; PHNO; scan; effect

Summary:

      The purpose of this study is to find out whether short term treatment with a antihypertensive
      medication prazosin, can influence the levels of a dopamine in the brain. We will examine the
      levels of dopamine in the the brain using Positron Emission Tomography (PET) and Magnetic
      Resonance Imaging (MRI). We hypothesize that there will be no significant changes in dopamine
      levels in healthy individuals taking prazosin.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Healthy males and females of any ethnic origin between 19 and 45 years old

        Exclusion Criteria:

          -  Use of any illicit drugs in past 3 months prior to randomization and/or have a current
             or past diagnosis of drug abuse/dependence (including alcohol)

          -  Current or past DSM-IV diagnosis of any Axis I psychiatric disorder

          -  Major psychiatric illness and/or substance dependence in first order relatives

          -  Current active or past suicidal ideation

          -  Baseline systolic blood pressure outside the normal range

          -  Current use of medications that could interact with prazosin (e.g. beta blockers,
             phosphodiesterasetype 5 inhibitors, indomethacin, verapamil, modafinil, clonidine)

          -  Current use or use during the previous month of medication that may affect the CNS at
             the time of scanning (e.g. neuroleptics, bupropion)

          -  Any significant abnormalities in baseline blood results (e.g. CBC, renal and hepatic
             indicators) or ECG readings that would preclude the use of prazosin

          -  Pregnancy, trying to become pregnant or breastfeeding

          -  Presence of metal objects in the body (e.g. some artificial joints, bone pins,
             surgical clips, skull plate, certain part of dental braces) or implanted electronic
             devices (e.g. cardiac pacemaker, neurostimulator), that preclude safe MR scanning

          -  Claustrophobia

          -  Participation in any nuclear medicine procedures that, including the dose received
             during participation in this study, will bring the total radiation dose over the
             currently approved guideline of 20mSv in a 12-month period

          -  Cardiovascular or cerebrovascular diseases

          -  History of or current neurological illnesses including seizure disorders, migraine,
             multiple sclerosis, movement disorders, head trauma, CVA or CNS tumor

          -  Abnormal body mass (defined as not within 20% of normal BMI

          -  Learning disability, amnesia or other conditions that impede memory and attention