Effectiveness of Prazosin for PTSD Patients

The drug prazosin* (Minipress and Minipress XL) has been around for years. It is a drug used for lowering blood pressure. However, ongoing studies for over a decade have shown that it effectively relieves PTSD-related nightmares. Although, this news is not considered “latest news,” enough Service members and their Families have not heard about prazosin, so providing information about this drug is necessary. Prazosin is an alpha-blocker that blocks alpha receptors in the brain and smooth muscle, which relaxes blood vessels, thus lowering blood pressure. It has a few side effects, such as headache, dizziness, lightheadedness, lack of energy, and fainting upon standing (orthostatic hypotension), but they tend to go away after awhile and studies show this medication has been well-tolerated. A complete list of side effects is available here: http://www.nlm.nih.gov/medlineplus/druginfo/meds/a682245.html

As with many medications, prazosin was studied as a potential treatment for other medical conditions. In 2003, The American Journal of Psychiatry published the results of a study that showed prazosin significantly reduced PTSD-related nightmares, sleep disturbances, and other distressing PTSD symptoms (e.g., re-experiencing, avoidance/numbing, and hyperarousal) compared to a placebo. The study can be found here: http://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.160.2.371

In 2012, the Mayo Clinic reviewed 12 studies examining the effectiveness of prazosin in curbing PTSD-related nightmares. Four of these studies were the gold standard for scientific research—randomized controlled trials. All 12 studies showed that prazosin worked rapidly to stop PTSD-related nightmares (e.g., days to weeks) and was well-tolerated because of the low number of side effects. The downside is, is that in many cases if Service members stopped taking the drug, their nightmares returned; however, restarting prazosin stopped the nightmares again, so it appears that taking prazosin may be a long-term treatment for most Service members. Importantly, the drug has been used for decades without serious long-term adverse effects and it is safe to take with other PTSD medications, except for trazodone. You can read the news release describing the Mayo Clinic review here: http://newsnetwork.mayoclinic.org/discussion/mayo-clinic-review-blood-pressure-drug-effective-for-treating-ptsd-related-nightmares/

How does prazosin work? PTSD-related nightmares are extremely frightening  and feel very real, such that they interrupt sleep patterns. This is ironic since it appears that these nightmares result from altered sleep patterns; they occur during periods of light sleep or disrupted REM (rapid eye movement) sleep. It is thought that norepinephrine plays a role. Norepinephrine, which is off-balance in those with PTSD, is a neurotransmitter (brain chemical) and hormone that is involved in the “fight or flight” response, and ultimately, the release of adrenaline, which not surprisingly, disturbs sleep patterns. Prazosin acts by blocking norepinephrine at alpha receptors, thus inducing deeper sleep and increasing REM sleep, which breaks the “nightmare cycle” and results in normalizing dreams and sleep patterns. By limiting the effects of norepinephrine, which also disrupts cognitive thinking and increases the fear response, prazosin reduces fear and improves cognitive thinking, sense of well-being, and overall ability to function. Prazosin costs pennies per day because of the availability of generics, the relatively low dosage (generally, 1 to 20 mg/day) required, and because Service members do not build tolerance to the drug that would require increasing the dosage. It is essential to stop PTSD-related nightmares because they can contribute to substance use and suicidal thinking (suicide ideation). Prazosin is the recommended first-line treatment for PTSD-related nightmares and sleep disturbances. See http://www.research.va.gov/resources/pubs/docs/va_research_currents_apr_07.pdf

for more information.

* Prazosin (generic of Minipress/Minipress XL) should not be confused with propranolol, also tried at one point to treat PTSD-related nightmares. Propranolol is a beta-blocker and it not only caused more PTSD-related nightmares, both in number and severity, but also increased sleep disturbances.