Minipress (Prazosin) for Stress Nightmares in PTSD

Minipress (prazosin), a drug commonly used to treat high blood pressure and urinary retention, has been shown in some studies to be safe and effective in managing nightmares and sleep disturbances in people with post-traumatic stress disorder (PTSD).

Minipress appears to block the responsiveness of norepinephrine, a chemical that triggers the body’s “fight or flight” response to real and perceived threats. By doing so, people with PTSD may enjoy fewer nightmares.

Minipress does not seem to have any effect in reducing nightmares in people without PTSD.

This article explains the causes of nightmares in people with PTSD and how Minipress can help. It also takes a look at the evidence supporting the claims and lists the possible risks and side effects of this off-label PTSD drug.

How Common Is PTSD?

Historically, only veterans coming home from combat were diagnosed with PTSD. Now, clinicians recognize patients who experience other types of traumatic events can also experience this condition.

Women are more than twice as likely as men to develop PTSD after experiencing or witnessing a traumatic event. Aside from the triggering event, a diagnosis of PTSD requires symptoms in each of five categories:

• Re-experiencing the event through unwanted memories, nightmares, flashbacks, or strong reactions to reminders of the event
• Avoiding reminders of the trauma, including people, places, and objects
• Negative changes in your mood and thoughts associated with the triggering event
• Chronic hyperarousal symptoms, which may include irritability, aggression, risk-taking, or hypervigilance
• Symptoms last longer than one month, create functional impairment, and aren't caused by medication or substance abuse.

How Prazosin Works to Treat Nightmares

Prazosin blocks responsiveness to norepinephrine, a stress hormone that affects your brain, at specialized chemical receptors called alpha-1 receptors. Receptors are the sites where cells transmit messages to each other. It is not clear how this specifically impacts sleep or dreams.

Other Therapeutic Uses

Clinical studies show prazosin might offer other therapeutic benefits to PTSD patients, but the results are mixed. One study suggested that taking prazosin:

• Significantly reduced daytime PTSD symptoms when patients already taking it took it in the daytime too, not just at night.
• It may have a beneficial effect on alcohol cravings for participants who were alcohol dependent and trying to stop drinking. This is important when you consider the number of PTSD patients who turn to alcohol for comfort and end up with an alcohol use disorder.

Who Should Not Use Prazosin

If you have previously had adverse reactions to this or similar medications, don’t take prazosin.

Prazosin isn't usually prescribed to those over age 65.

People in the following groups should use prazosin with caution. Be sure to tell your healthcare provider if any of the following apply to you:

• Low blood pressure
• Narcolepsy
• A history of liver disease or prostate cancer
• If you're pregnant or could become pregnant
• If you're breastfeeding
  
• If you’re going to have any surgery, including cataract surgery or dental surgery

Common Side Effects

Prazosin can cause side effects. In clinical trials, these included:

• Drowsiness in 7.6% of patients
• Lack of energy in 6.9% of patients
• Weakness in 6.5% of patients
• Dizziness in 10.3% of patients
• Nausea in 4.9% of patients
• Palpitations (irregular heartbeats) in 5.3% of patients
• Headache in 7.8% of patients
  

Additional side effects of prazosin that occur in 1–4% of patients include:

• Vomiting
• Diarrhea and/or constipation
• Orthostatic hypotension (a form of low blood pressure triggered by standing up from a seated position too quickly)
• Depression
• Nasal congestion
• Fainting

Safety Precautions

As described above, certain people should use prazosin with caution or not at all. The safety of its use while pregnant or breastfeeding is not known, so these populations should use caution. It may also be important to monitor your blood pressure with prazosin use so that it does not become too low and cause fainting or falls.

A Word From Verywell

If you experience any difficulties, you should be in close contact with your primary healthcare provider. PTSD is a serious condition and it deserves treatment. Don’t suffer in silence: reach out to get the help that you need to sleep more normally. If you suffer from depression or experience thoughts of suicide, dial 988 to contact the 988 Suicide & Crisis Lifeline and connect with a trained counselor. If you or a loved one are in immediate danger, call 911.