The Effects of Prazosin on Dopamine in Healthy Humans: A PET Pilot Study

Healthy Clinical Trial

Official title:

Exploring the Effects of Prazosin on Basal Dopamine in Healthy Humans: A [11C]-(+)-PHNO PET Pilot Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01999530
• Other study ID #: 224/2012
• Status: Completed
• Phase: Phase 1
• Start date: November 2013
• Est. completion date: August 2016

Study information

• Verified date: May 2019
• Source: Centre for Addiction and Mental Health
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Description:

The purpose of this study is to find out whether short term treatment with a antihypertensive medication prazosin, can influence the levels of 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). The study will involve three PET scans and one MRI. One PET scan will be performed before the participants take prazosin for approximately three weeks, and the last two PET scans will be performed after the prazosin medication phase. We hypothesize that there will be no significant changes in dopamine levels in healthy individuals taking prazosin.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: August 2016
• Est. primary completion date: August 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 19 Years to 45 Years

Eligibility

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

Related Conditions & MeSH terms

• Healthy

Intervention

Drug:
• Prazosin Hydrochloride
Gradual upward titration to 15mg/day for approximately three weeks.

Locations

Country	Name	City	State
Canada	Centre for Addiction and Mental Health	Toronto	Ontario

Sponsors (3)

Lead Sponsor	Collaborator
Centre for Addiction and Mental Health	Ontario Lung Association, Pfizer

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Changes in [11C]-(+)-PHNO Binding (Measured as Binding Potential) in Dorsal Caudate (DC)	Binding potential (an estimate of the ratio of Bmax/kd) was measured by positron emission tomography to determine if taking prazosin alters the amount of tracer bound to receptors. A negative change in binding potential means a decrease in binding potential and a positive change in binding potential represents an increase. Bmax is the total density of receptors. kd is the affinity of a drug for the target	3 weeks after taking prazosin

External Links

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