Alpha-1 adrenergic antagonist
Blocks postsynaptic alpha-1 adrenergic receptors, reducing sympathetic outflow and lowering blood pressure; modulates central noradrenergic activity, which may reduce nightmares and hyperarousal symptoms in post-traumatic stress disorder (PTSD).
Hypertension, benign prostatic hyperplasia
PTSD-related nightmares and anxiety
Oral tablets
Start at 1 mg p.o. nightly, titrate slowly based on clinical response and tolerability, typical dose range 1–20 mg/day
1–20 mg/day depending on indication
Half-life ~2–3 hours, metabolized hepatically, excreted renally
Dizziness, headache, drowsiness, palpitations, first-dose hypotension
Orthostatic hypotension, syncope (especially with initial dose)
Regular blood pressure monitoring, watch for orthostatic hypotension especially at initiation
None
Use caution in elderly patients due to increased risk of hypotension and falls. In traumatic brain injury (TBI), prazosin may be beneficial for managing trauma-related nightmares and sleep disturbances, particularly when comorbid with PTSD.