Can Prazosin Be Prescribed for Night Terrors with Blood Pressure 102/72?
Yes, prazosin can be safely prescribed for night terrors at this blood pressure, starting with 1 mg at bedtime with appropriate monitoring for orthostatic hypotension. 1, 2
Blood Pressure Considerations
Your patient's current BP of 102/72 mmHg is not a contraindication to prazosin initiation, though it warrants careful monitoring:
- The FDA mandates starting all patients on 1 mg capsules regardless of blood pressure to minimize risk of first-dose syncope, which occurs in approximately 1% of patients started on doses ≥2 mg 2
- Syncopal episodes typically occur within 30-90 minutes of the initial dose and are believed to result from excessive postural hypotension 2
- The blood pressure reading of 102/72 mmHg is lower than the previous 125/75 mmHg, but this does not preclude prazosin use—it simply requires more vigilant monitoring 1, 2
Specific Initiation Protocol
Start with 1 mg at bedtime and monitor blood pressure after the first dose and with each increase: 1, 2
- Increase by 1-2 mg every few days until clinical response is achieved 1
- For civilians with trauma-related nightmares/night terrors, the average effective dose is 3-4 mg/day (mean 3.1 ± 1.3 mg) 1
- Military veterans typically require higher doses (9.5-15.6 mg/day), but this is likely not applicable to your patient 1
Critical Safety Measures
Counsel the patient on orthostatic precautions before the first dose: 2
- More common than syncope are dizziness and lightheadedness associated with blood pressure lowering 2
- Advise the patient to avoid situations where injury could result should syncope occur during initiation 2
- If syncope occurs, place the patient in recumbent position; this adverse effect is self-limiting and typically does not recur after initial therapy 2
Monitoring Strategy
Check orthostatic vital signs after the first dose and with each significant dose increase: 1
- Transient orthostatic hypotension may occur but usually resolves during treatment 1
- The lower baseline BP (102/72 mmHg) increases risk of symptomatic hypotension, so consider checking BP 30-90 minutes post-dose initially 2
- Assess nightmare frequency and intensity using standardized measures when possible 1
Common Pitfalls to Avoid
Do not start with 2 mg or 5 mg capsules—these are not indicated for initial therapy: 2
- The 1 mg starting dose is mandatory per FDA labeling to minimize syncope risk 2
- Do not add other antihypertensive medications without reducing prazosin to 1-2 mg three times daily and retitrating 2
- Be aware that if the patient is on PDE-5 inhibitors, additive blood pressure lowering can occur 2
Expected Outcomes
Prazosin demonstrates favorable clinical efficacy for trauma-related nightmares with relatively rapid response within weeks: 3
- The American Academy of Sleep Medicine gives prazosin a Level A recommendation for PTSD-associated nightmares 4
- However, nightmares may return to baseline intensity if prazosin is discontinued, so this is not a curative treatment 1, 4
- Prazosin works by reducing CNS sympathetic outflow through alpha-1 adrenergic receptor blockade 4, 5
Alternative Considerations
If prazosin is not tolerated due to hypotension, consider clonidine (0.2-0.6 mg in divided doses), though it has less robust evidence and also carries risk of postural hypotension 6, 5