What is the recommended dosing of prazosin for the treatment of night terrors?

Prazosin Dosing for Night Terrors in PTSD

The recommended dosing of prazosin for night terrors in PTSD patients is to start at 1 mg at bedtime and titrate up by 1-2 mg every 3-7 days, with a typical effective dose range of 1-10+ mg. 1

Dosing Protocol

Initial Dosing

• Start with 1 mg at bedtime 1, 2
• Monitor for orthostatic hypotension after the first dose 1
• Initial low dosing is critical as prazosin can cause first-dose hypotension 3

Titration Schedule

• Increase by 1-2 mg every 3-7 days 1
• Titrate upward until desired reduction or absence of nightmares is achieved 2
• Adjust according to individual blood pressure response 3

Effective Dosing Ranges

• Typical effective dose: 3 mg (range 1-10+ mg) 1
• Military veterans may require higher doses:
  • Mean effective dose in military studies: 8.9-15.6 mg 4
  • Men typically require higher doses (15.6 ± 6.0 mg) than women (7.0 ± 3.5 mg) 4
  • Some studies report using up to 20 mg at bedtime 2

Maximum Dosing

• Standard maximum: 20 mg daily 3, 2
• Some treatment-resistant cases may benefit from higher doses (up to 30-45 mg), though this exceeds standard recommendations 5
• Doses higher than 20 mg usually do not increase efficacy for most patients 3

Monitoring and Assessment

• Evaluate orthostatic hypotension, especially after the first dose 1
• Monitor blood pressure regularly during titration 1
• Assess treatment response after 4-6 weeks at maximum tolerated dose 1
• Use standardized measures or sleep diaries to track nightmare frequency and intensity 1

Important Considerations

• Prazosin has Level A evidence (highest recommendation) from the American Academy of Sleep Medicine for PTSD-related nightmares 1
• Response is typically seen within weeks 6
• Underdosing is a common pitfall - many patients require doses higher than the initial 1 mg 1
• Consider twice-daily dosing for some patients (morning and bedtime) 4
• When used with PDE-5 inhibitors, start the PDE-5 inhibitor at the lowest dose due to additive hypotensive effects 3

Cautions

• First-dose hypotension is a significant concern; consider administering the first dose when the patient can remain recumbent 3
• When adding other antihypertensive medications, reduce prazosin dose to 1-2 mg and retitrate 3
• Discontinuation can lead to return of nightmares to baseline intensity 4
• Side effects are generally mild and include dizziness and orthostatic hypotension 4

Prazosin offers significant benefits for PTSD-related nightmares with a relatively favorable side effect profile compared to other medications, making it a first-line pharmacological treatment for this indication.