prazosin for ptsd

PTSD: disorder that develops after exposure to traumatic event involving actual or threatened injury to themselves or others

• presents as: intrusive thoughts, nightmares, flashbacks, avoidance of reminders of the traumas, sleep disturbances
• leads to dysfunction in life
• 70% of patients with PTSD have sleep disturbances
• Mechanism unknown:
• increased central nervous system noradrenergic activity might contribute to pathophysiology
• elevated levels of norepinephrine disturb REM sleep and increase non-REM sleep
• prazosin decreases the arousal produced by norepinephrine in response to a stressor
• specific involvement of postsynaptic alpha 1 adrenoreceptor
• nightmares usually present during light sleep and disturb REM sleep
• prazosin has a role (mechanism unknown) in regulating REM sleep
• diagnosis made if having still having symptoms at least 4 weeks after traumatic event
• early initiation of treatment is best
• can be treated with SSRI's, SNRI's, TCAs, MAOIs, atypical antidepressants, second generation antipsychotics (augmentation).
• alpha-adrenergic receptor blocker: prazosin
• acts centrally (crosses BBB-highly lipophilic) and peripherally
• reduces nightmares
• improves sleep
• 1 mg at bedtime, gradually increase to 3-15 mg as tolerated
• avoid sudden d/c (can result in rebound hypertension)
• often used in conjunction with one of the antidepressant options (^ usually SSRIs)
• use in caution in patients with hypotension, prone to orthostatic hypotension
• studies show well-tolerated and successful improvement in symptoms of PTSD
• side effects: hypotension, dizziness, lightheadedness, orthostatic hypotension, sedation, syncope