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Effect of Prazosin on Neurophysiology and Cognition in Post-Traumatic Stress Disorder (PTSD)

This study has been withdrawn prior to enrollment.
(Primary investigator left VA employment)
Information provided by (Responsible Party):
VA Office of Research and Development Identifier:
First received: April 28, 2009
Last updated: September 20, 2013
Last verified: September 2013
In this study, the investigators are looking at how PTSD affects things such as memory, attention, reaction to sounds, eye movements, and heart rate. The investigators are also studying whether a medication called prazosin has an effect on these things.

Condition Intervention
Posttraumatic Stress Disorder Drug: prazosin hydrochloride Drug: placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double
Primary Purpose: Basic Science
Official Title: Effect of Prazosin on Neurophysiologic Responses and Cognitive Performance in PTSD

Resource links provided by NLM:

Further study details as provided by VA Office of Research and Development:

Primary Outcome Measures:
  • Responses to acoustic startle and prepulse inhibition of acoustic startle [ Time Frame: baseline, week 2, week 8 ]

Secondary Outcome Measures:
  • Heart rate variability [ Time Frame: baseline, week 2, week 8 ]
  • Pennsylvania Computerized Neurocognitive Battery (CNB) [ Time Frame: baseline, week 8 ]

Enrollment: 0
Study Start Date: December 2009
Study Completion Date: September 2011
Primary Completion Date: June 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Arm 1
Persons with PTSD
Drug: prazosin hydrochloride
prazosin 1-20 mg/day in divided doses
Other Name: Minipress
Placebo Comparator: Arm 2
Persons with PTSD
Drug: placebo

Detailed Description:
Converging lines of evidence suggest that central nor adrenergic function is perturbed in PTSD. Placebo-controlled trials demonstrate that the centrally acting alpha-1 antagonist prazosin is clinically effective for several core symptoms of PTSD in combat veterans. However, no detailed assessment of the impact of prazosin on human neurophysiology and cognition have been conducted. Our hypotheses are based on studies that demonstrate (1) the importance of central adrenergic receptors in regulating fundamental neurophysiologic and cognitive functions, (2) the alteration of these functions in PTSD, and (3) the efficacy of prazosin in improving the clinical symptoms of PTSD. The primary objective of this study is to measure the subtle neurocognitive and neurophysiologic effects on prazosin in combat veterans with PTSD.

Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Exposure to one or more life-threatening war zone trauma events;
  • DSM-IV diagnosis of PTSD derived from the Clinician-Administered PTSD Scale (CAPS), CAPS total score greater than or equal to 50;
  • CAPS recurrent distressing dreams item score greater than or equal to 5 (of a maximum score of 8), with a frequency rating greater than or equal to 2 (of 4);
  • stable dose of non-exclusionary medications and psychotherapeutic treatment for at least 4 weeks prior to randomization;
  • good general medical health;
  • female participants must agree to use a reliable form of birth control throughout study.

Exclusion Criteria:

  • Acute or unstable chronic medical illness;
  • diagnosis of current schizophrenia, schizoaffective disorder, psychotic disorder not otherwise specified, bipolar disorder, delirium, or cognitive disorder;
  • severe psychiatric instability or severe situational life crises;
  • substance dependence disorder currently or in past 3 months;
  • current cocaine or stimulant abuse or evidence of acute intoxication on alcohol or nonprescribed medication;
  • allergy or previous adverse reaction to prazosin or other alpha-1 adrenergic antagonists;
  • serious head injury with loss of consciousness of greater than 30 minutes;
  • current diagnosis of seizure disorder;
  • current use of prazosin or other alpha-1 adrenergic antagonists;
  • current use of atypical antipsychotic medication;
  • stimulants or alternative medications with stimulant properties (e.g. ephedra), certain exposure therapies must be completed at least 4 weeks before baseline;
  • certain medications (trazodone, erectile disfunction medications) are not allowed or are restricted during the study;
  • women must not be pregnant or nursing during the study.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00890643

United States, Washington
VA Puget Sound Health Care System
Seattle, Washington, United States, 98109
Sponsors and Collaborators
VA Office of Research and Development
Principal Investigator: Dorcas J. Dobie, MD VA Puget Sound Health Care System
  More Information

Responsible Party: VA Office of Research and Development Identifier: NCT00890643     History of Changes
Other Study ID Numbers: MHBA-018-08S
Study First Received: April 28, 2009
Last Updated: September 20, 2013

Keywords provided by VA Office of Research and Development:
Stress disorders, post-traumatic
Combat Disorders

Additional relevant MeSH terms:
Stress Disorders, Traumatic
Stress Disorders, Post-Traumatic
Pathologic Processes
Trauma and Stressor Related Disorders
Mental Disorders
Antihypertensive Agents
Adrenergic alpha-1 Receptor Antagonists
Adrenergic alpha-Antagonists
Adrenergic Antagonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs processed this record on September 21, 2017