Prazosin for Post-Concussive Headaches

  • End date
    Dec 30, 2022
  • participants needed
  • sponsor
    Seattle Institute for Biomedical and Clinical Research
Updated on 24 February 2022


Mild traumatic brain injury (mTBI) caused by blast effects of explosive devices has been called the "signature injury" of soldiers who served in the Iraq and Afghanistan conflicts. mTBI can also occur from impact or hitting the head on an object or the ground. Although termed "mild" in comparison to major brain injuries, people with mTBI can have problems with their memory and concentration. People with mTBI can also find they are more irritable, have more anxiety, and have trouble with their mood and sleep.

The purpose of this study is to see if a medication called prazosin can help treat chronic headaches in people with mTBI. The Food and Drug Administration (FDA) has approved prazosin for treating people with high blood pressure. At this time, the FDA has not approved prazosin in the treatment of mTBI or headaches. Some people who have posttraumatic stress disorder (PTSD) and have been taking prazosin for their medical conditions or who have taken it in research studies have said they have fewer headaches.


Background and Rationale: Headaches following mild traumatic brain injury (mTBI) are common, can be refractory to standard therapies, and may persist and worsen to become a debilitating chronic pain syndrome. The purpose of this study is to evaluate the centrally acting alpha-1 adrenoreceptor (AR) antagonist drug prazosin as a prophylactic treatment for chronic posttraumatic headaches (PTHAs). The impetus for this study comes from a large open-label case series in Iraq and Afghanistan Veterans with mTBI and PTHAs and data from a placebo-controlled trial evaluating use of prazosin for posttraumatic stress disorder (PTSD) in active-duty Servicemembers (SMs). Findings from these studies showed that in addition to decreasing PTSD-related symptoms and improving sleep quality, prazosin decreased the frequency and severity of headaches, which were common in the study populations.

Study Objectives, Specific Aims, and Hypotheses: The objective of this study is to evaluate the efficacy of prazosin as a prophylactic treatment for persistent PTHAs, which will be accomplished by conducting a randomized placebo-controlled double blind trial of prazosin vs. placebo in active-duty SMs and Veterans who were in military service at any time from October 7, 2001 to the present with persistent PTHAs.

  • Specific Aim 1: To determine the effect of prazosin compared to placebo on headache frequency, headache severity and duration, use of abortive/analgesic medications, and headache-related disability.
  • Specific Aim 2: To determine the effect of prazosin on sleep disturbance, PTSD symptoms, depressive symptoms, alcohol consumption, global cognitive function, health-related quality of life, and global clinical status.

Condition Post-Traumatic Headache
Treatment placebos, Prazosin
Clinical Study IdentifierNCT02965027
SponsorSeattle Institute for Biomedical and Clinical Research
Last Modified on24 February 2022


Yes No Not Sure

Inclusion Criteria

Male and female Active-duty SMs or Veterans aged 18 or older who are in good general health
History of blast and/or impact head trauma mTBI meeting Defense and Veterans Brain Injury Center (DVBIC) mTBI criteria
Mild TBI is defined as an injury to the head causing at least one of the following: alteration in consciousness (for up to 24 hours after the injury), loss of consciousness (0-30 minutes), and/or post-traumatic amnesia (up to 1 day post-injury). If available, the Glasgow Coma Scale score must be 13-15, and head imaging findings (if imaging was performed) must be negative
Frequent HAs that started within 3 months after a head injury or marked worsening (a two-fold or greater increase in frequency and/or severity) of pre-existing headaches within 3 months of head injury
HAs either 1) must last 4 or more hours a day and reach a moderate to severe intensity at any point during the headache, or 2) may be of any severity or duration if the participant takes a medication or other agent in an effort to stop or treat a headache
HAs meeting these criteria must have been present on average at least 8 days per 4-week period and occurring at a stable level by self-report for at least 3 months prior to the Initial Screening Visit. The 4-week HA frequency/severity criteria must be confirmed during the Preliminary Screening Period
Participants of childbearing potential must agree to abstain from sexual relations that could result in pregnancy or use an effective method of birth control acceptable to both participant and the clinician prescriber during the study. Participants who are not of childbearing potential are not required to use contraception during the study
Participants must have English fluency sufficient to complete study measures

Exclusion Criteria

Participation in other interventional research
History of penetrating head injury
History of TBI more severe than mild by DVBIC criteria
A primary non migraine and/or tension-type HA disorder (for example hemicrania continua; cluster) that accounts for the majority of current symptoms
HAs of any kind of moderate or severe intensity on an average of more than 4 days per month preceding the concussive trauma
Acute or serious medical illness or unstable chronic medical illness (e.g., unstable angina, myocardial infarction within 6 months, congestive heart failure, clinically significant or concerning cardiac arrhythmias; preexisting hypotension [systolic blood pressure<110] or orthostatic hypotension [systolic drop >20 mm Hg after 2 min standing accompanied by lightheadedness], chronic renal or hepatic failure, or acute pancreatitis. The eligibility of potential participants having acute serious and/or chronic medical illnesses other than those listed will be evaluated on a case-by-case basis by a study physician, PA-C, or ARNP
Use of prazosin or other alpha-1 antagonist (including but not limited to alfuzosin, doxazosin, silodosin, tamsulosin, terazosin) for any purpose in the 2 weeks prior to initial screen (P1) visit and prohibited throughout the study
Allergy or previous adverse reaction to prazosin or other alpha-1 antagonist
Active psychosis or psychotic disorder, severe depression (as determined per clinician prescriber judgment), severe psychiatric instability or severe situational life crisis (including evidence of being actively suicidal or homicidal)
Meets Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria for any Substance Use Disorder except caffeine-related disorders, or tobacco-related disorders
History of delirium within the prior 3 months, epilepsy, stroke, dementia, psychotic disorder, or bipolar disorder
Structural brain abnormalities on any prior imaging with associated clinically evident manifestations
Current participation in transcranial magnetic stimulation studies
Women of childbearing potential must not be pregnant, planning to become pregnant during the study period, or nursing
Participation in a HA support group or other activity such as meditation or yoga intended to mitigate HA or other chronic pain must be stable at least 4 weeks prior to beginning the initial screen (P1) visit and may not be started during the study
Failure to record HA data for at least 80% of days during the Screening Period
Not suitable for study per clinician judgement
Medication-and other Treatment-Related Considerations
The use of HA rescue or symptom-relieving medications will be allowed during the study. This includes triptans, ergotamines, opioids, simple analgesics (e.g. acetaminophen, aspirin, or non-steroidal anti-inflammatories [NSAIDS], and combination analgesics. Their use will be recorded on the concurrent medication CRF during the Preliminary Screening Period (P1) and throughout the remainder of the study. Randomization of participants will be stratified based on whether their use of HA medications meets ICHD-3 beta criteria for overuse of these medications, as described in section 5.5 below
Opioid Medications: Use of opioids for treatment of HA or non-HA-related pain or for any other purpose is allowed during the study. Any opioid use would ideally be excluded due to potential confounding effects on interpretation of response to treatment. However, in this population, particularly in Veterans with chronic pain or undergoing minor orthopedic or dental procedures, opioid use is common. Use of opioids, including frequency and dose, will be recorded on the concurrent medication CRF
Cannabis: The use of cannabis in any form is not excluded unless its use meets criteria for Cannabis Use Disorder. All use of cannabis will be documented
Other Medications: Participants who are using other medications or treatments on a routine basis must be on a stable dose for at least 4 weeks prior to the Preliminary Screening Period (P1), and must intend to continue the medication at the same regimen for the duration of the trial unless lack of efficacy, safety, or tolerability dictates otherwise. The following medications and treatments are not excluded
Psychoactive drugs (for example, anticonvulsants, benzodiazepines, antidepressants, sedative/hypnotics)
Antihypertensive medications (including beta-blockers, calcium channel blockers, angiotensin converting enzyme [ACE] inhibitors, and angiotensin receptor blockers)
The use of magnesium in any dose that is prescribed for the purpose of HA prevention or treatment. The incidental use of magnesium in multi-vitamins, laxatives, etc. is permissible but must be documented
Hormones (for example, testosterone, estrogen, or progesterone) in any form
Onabotulinum toxin A and nerve block injections for the purpose of HA prevention are permissible if the treatment response has been stable during the two most recent treatment cycles
The "as-needed" (prn) use of any non-exclusionary medications is allowed; however, such use must be discussed with a clinician prescriber and documented
The use of butalbital in any form within 4 weeks of beginning the Preliminary Screening Period (P1) through the end of the participant's study involvement is exclusionary
Participants who have been taking trazodone will undergo a 2-week washout period before the Preliminary Screening Period (P1 visit). Combining prazosin and trazodone may increase the risk of priapism. We have decided to begin the washout period before the Preliminary Screening Period in order to remove any confounding variables while on the headache log and actigraphy
Sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil (Stendra) will not be permitted during the study drug dose Titration Period, because of increased risk of hypotension in combination with alpha-1 blockers, but will be allowed at half the usual starting dose following the study drug dose Titration Period, per VA prescribing guidelines
Use of supplements containing nitrates and supplements containing stimulants (such as ephedra) are exclusionary in the two weeks prior to initial screen (P1) visit and prohibited throughout the study. Participants who take these supplements will be asked to discontinue them for a minimum of two weeks before the Preliminary Screening Period (P1 visit)
Use of prescribed stimulants (such as amphetamine or dextroamphetamine containing medications) is exclusionary in the 2 weeks prior to the initial screen (P1) visit and prohibited throughout the study. Participants who take these medications will be asked to discontinue them for a minimum of 2 weeks before the Preliminary Screening Period
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