What is your approach to using prazosin to treat day-time symptoms in PTSD?

I use doxazosin, which has a very similar mechanism of action (it hits different subunits on the alpha receptor), but it does not have as much of an effect on blood pressure, which can limit the dosing of prazosin. It also does not have as many other side effects documented, such as palpitations.

The half-life of doxazosin is 21 hours, compared to the half-life of prazosin, which is 3 hours. Theoretically, this could possibly help with hypervigilant symptoms during the day. I found that some vet...

I will only use prazosin during the day if the patient is using it for sleep disturbance/nightmares. If they are not using prazosin, then I prefer guanfacine during the day.

If using prazosin, I start at 0.5 mg in the morning and then BID. I will titrate up based on reaction and side effects.

• Prazosin does not have evidence to treat symptoms other than nightmares from PTSD.
• Typically, it works very well for trauma-related nightmares and general nightmares that disrupt sleep.
• Since I treat teens/children, I hardly use AM dosage of prazosin; however, in adults, lower dosages have been used in the AM with higher dosages at HS.
• I have never used it as PRN, and there is no evidence to support this.

Schnurr et al., PMID 38408360