Prazosin Ineffective for Preventing Suicidal Thoughts — May Worsen Nightmares

The blood pressure drug prazosin has been gaining popularity as a treatment for post-traumatic stress disorder (PTSD), with some research indicating that it could reduce nightmares or protect against suicidal thoughts. However, a new study, just published in the Journal of Clinical Psychopharmacology, found that prazosin was associated with increased insomnia and nightmares, and did not reduce suicidal thoughts.

Although an early study from 2013 suggested that prazosin might have reduced nightmares for active-duty soldiers with a PTSD diagnosis, the findings were more equivocal than reported. Only 3 of the 67 participants met criteria for remission of symptoms at the end of the study, and there were no differences on the measures of PTSD symptoms of reexperiencing and avoidance. There were also no improvements on either the HAM-D or the PHQ-9 depression scales.

More recent research has been even more discouraging regarding prazosin’s effectiveness at reducing nightmares. Another study from this year found that prazosin did not significantly reduce nightmares or improve sleep quality. This study included a larger sample (304 veterans).

However, fewer veterans in the prazosin group developed new or worsening suicidal thoughts (8% in that group, compared to 15% in the placebo group). Because of this, it was hypothesized that prazosin might protect against suicidal thoughts.

The current study, led by William McCall at the Medical College of Georgia, Augusta University, was designed to follow up on this hypothesis. It included 20 participants, all of whom had a PTSD diagnosis and reported suicidal thoughts. They were randomly assigned into two groups, so 10 participants received prazosin, while the other 10 received a placebo.

Unfortunately, the researchers found that prazosin had no effect on suicidal thoughts, and may have worsened nightmares and insomnia. According to McCall and the other researcher:

“Nighttime measures of nightmares and insomnia showed significantly less improvement in the prazosin group,” and “prazosin showed no signal on daytime measures including suicidal ideation.”

According to the researchers, the clinical impact of prazosin is now unclear. Although their study was small, the finding of worsening symptoms is concerning for a drug to treat PTSD. They write that the research does not support using prazosin for nighttime symptoms such as nightmares.

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McCall, W. V., Pillai, A., Case, D., McCloud, L., Nolla, T., Branch, F. . . . Rosenquist, P. B. (2018). A pilot, randomized clinical trial of bedtime doses of prazosin versus placebo in suicidal posttraumatic stress disorder patients with nightmares. Journal of Clinical Psychopharmacology, 38(6), 618-621. doi: 10.1097/JCP.0000000000000968 (Link)