PTSD and Prazosin: High Dose for Resistant PTSD Nightmares.

Q: Patient is a 30 year old male with diagnosis of PTSD. Prazosin was gradually titrated to 3 mg daily dose with minimal improvement in intrusive nightmares symptoms or sleep quality.
What is the highest prazosin dose needed for resistant PTSD nightmares in male patients?











Higher dose of prazosin may be needed for treatment resistant PTSD nightmares. This post will focus on articles published on this topic.



STUDY 1: This retrospective chart review done at VA Veterans Affairs Medical Center (VAMC) examined the efficacy of various medications including prazosin in actual treatment of PTSD nightmares (1).

According to this study dose > 25 mg is needed for treatment resistant PTSD nightmares management.


STUDY 2: A 15 week randomized controlled trial (2) of prazosin in soldiers serving in Iraq and Afghanistan found following effective doses to be effective for trauma nightmares, sleep quality, global function, CAPS score, and the CAPS hyperarousal symptom cluster.



Mid Morning



(~30 yr age)


4 mg

15.6 mg

25 mg/day


1.7 mg

7 mg

12 mg/day


STUDY 3: Two case reports also showed efficacy of higher doses of prazosin in resistant PTSD nightmares (3).

Dose used was 30 mg and 45 mg without adverse side effects.



Case 1 (50 yr old female):

    • Prazosin was initiated at 1 mg daily dose, and gradually titrated based on response over 20 weeks to 15 mg in the morning, 10 mg at noon and 20 mg at night. 


  • Each time prazosin was increased by 2 mg daily to target a specific daytime or nighttime symptom. 


Case 2 (46 yr old females):

  • Prazosin was started at 1 mg orally at bedtime and was gradually titrated over 4 weeks to 15 mg in the morning, 5 mg at noon and 10 mg at bedtime based on response. 


Daytime dose was higher than nighttime dose in both cases because daytime symptoms were more distressing than nightmares.

Note that most recent randomized trial involving military veterans who had chronic PTSD, prazosin did not alleviate distressing dreams or improve sleep quality. (5)




    1. J Clin Med. 2016 Dec; 5(12): 117.
    2. Am J Psychiatry. 2013 Sep; 170(9):1003-10.
    3. Ther Adv Psychopharmacol. 2014 Feb; 4(1):43-7.
    4. Prazosin package insert.
    5. N Engl J Med. 2018 Feb 8;378(6):507-517.

Please do post your questions or comments below. 

Dr. Harvinder Singh, M.D. (Admin)

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