Minipress (Prazosin) for Stress Nightmares in PTSD

Physicians prescribe prazosin, sold under the brand name of Minipress, to treat nightmares for post-traumatic stress disorder (PTSD). Oddly enough, this medication does not seem to be as effective in patients with non-PTSD nightmares.

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 suffer from this debilitating mental condition.

By some estimates, about 8 percent of men and 20 percent of women who experience a traumatic event themselves or watch one happen as a non-participant get PTSD. Aside from the triggering event, you must also develop four general symptoms to receive a diagnosis:

• Re-experiencing the event even though it's over
• 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 make you feel stressed and angry

How Prazosin Works to Treat Nightmares

Prazosin blocks 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 military personnel already taking it took it in the daytime too.
• 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

There are only a few circumstances where you should not take prazosin or use it with caution:

• If you have previously had adverse reactions to this or similar medications, don't take prazosin.
• If you've had cataract surgery, take prazosin with caution.
• Prazosin should be used with caution if you have low blood pressure.

Of course, your physician can help you determine whether these circumstances apply to your case.

Common Side Effects

Prazosin can cause side effects. By one estimate, these include:

• Drowsiness, in 8 percent of patients
• Lack of energy, in 7 percent of patients
• Weakness, in 7 percent of patients
• Dizziness, in 10 percent of patients, and nausea in 5 percent of patients
• Palpitations (irregular heartbeats), in 5 percent of patients
• Headache, in 8 percent of patients

Additional side effects of prazosin that occur in 1 to 4 percent 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, reach out for help by calling the toll-free suicide prevention lifeline at 1-800-273-8255.