Treatment of Post-Traumatic Stress Disorders with the Alpha-1 Adrenergic Antagonist Prazosin: A Review of Outcome Studies

Objective: The present review aims to assess the clinical efficacy and safety of the α-1-adrenergic antagonist prazosin as primary pharmacologic treatment for post-traumatic stress disorder (PTSD). Method: A systematic review was performed using keywords (i.e., prazosin, α-1-adrenergic antagonist, α-1-blocker, post-traumatic stress disorder) in the databases PubMed/Medline (1966–May 2016), Embase (1966–May 2016), ScienceDirect (1823–May 2016), OvidSP (1946–May 2016) and Nature (1845–May 2016). To be considered for inclusion, studies had to test the efficacy of prazosin either alone or added to ongoing treatment in adults with PTSD, use validated tools to assess and monitor the disorders, allow comparisons on the basis of univariate analyses (i.e., p-values of t-tests and effect sizes) and list the identified adverse reactions. Results: 12 studies were included: 5 randomized controlled trials, 4 open-label prospective trials and 3 retrospective file reviews. The evaluation concerned 276 patients exposed to civilian trauma (19%) or war trauma (81%). Prazosin significantly decreases trauma nightmares, avoidance, hypervigilance and improves patient status in all studies. No significant difference of blood pressure was observed at the end of trials. Conclusions: Beyond the methodological and clinical biases of these studies, the present review not only confirms the effectiveness and good tolerability of prazosin, but also suggests its possible use as primary pharmacologic treatment for PTSD. Uncertainties remain, however, regarding the prescription modalities and dosages.