prazosin

Adjunctive therapy

Brands: MINIPRESS

Last reviewed 2025-12-28

Reviewed by PsychMed Editorial Team.

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Quick answers

What is prazosin?
Prazosin (brand Minipress) is an alpha-1 blocker approved for hypertension and commonly used off label to reduce PTSD-related nightmares and sleep disruption.
What is MINIPRESS?
MINIPRESS is a brand name for prazosin.
What is MINIPRESS (prazosin) used for?
Label indications include: Hypertension (label); commonly used off label for PTSD-related nightmares.
What drug class is MINIPRESS (prazosin)?
Alpha-1 adrenergic antagonist; reduces sympathetic tone (vasodilation).
What strengths does MINIPRESS (prazosin) come in?
Capsules: 1 mg, 2 mg, 5 mg.

Snapshot

Class: Adjunctive therapy
Common US brands: MINIPRESS
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2025-12-28

Label indications

Hypertension (label); commonly used off label for PTSD-related nightmares.

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Clinical Highlights

Prazosin (brand Minipress) is an alpha-1 blocker approved for hypertension and commonly used off label to reduce PTSD-related nightmares and sleep disruption. Evidence is mixed: some trials show meaningful improvements in nightmares and sleep quality, while a large veteran trial was negative; treat it as a symptom-targeted adjunct with reassessment milestones.

Prazosin is most useful when nightmares are a prominent driver of sleep disruption and baseline blood pressure can tolerate an alpha-1 blocker; document baseline vitals, define success metrics, and stop rather than continuing indefinitely if benefit is unclear.
First-dose syncope and orthostatic hypotension are the key early risks. Start low at bedtime and titrate slowly, especially in older adults or when combined with other blood-pressure-lowering medications.
The compare view and the prazosin evidence feed can help weigh alternative sleep strategies, and the prazosin print page can support safety counseling.
Approved for hypertension; PTSD-related nightmare and sleep disruption use is off label and should be paired with trauma-focused psychotherapy and first-line PTSD treatments rather than used as a standalone plan.
Generic capsules are widely available and inexpensive, which makes explicit follow-up and deprescribing plans important once nightmares improve or if benefit does not emerge.

Dosing & Formulations

Capsules: 1 mg, 2 mg, 5 mg. PTSD nightmares (off label): start 1 mg at bedtime; increase gradually (often by 1 mg increments) based on nightmare frequency and blood pressure/orthostasis.

If daytime hyperarousal symptoms are targeted, consider divided dosing with careful blood pressure monitoring.
If doses are missed for several days, consider restarting at a low dose and retitrating to reduce first-dose syncope risk.
Do not “catch up” missed doses; prioritize safety, retitrate as needed, and reassess for alternative nightmare/sleep strategies if titration is limited by hypotension.

Monitoring & Risks

Orthostatic hypotension and syncope: highest risk at initiation and after dose increases; counsel slow positional changes and hydration. Dizziness/fatigue: common during titration; reassess fall risk.

Headache and nasal congestion: may occur.
Hypotension risk increases when combined with other antihypertensives, dehydration, or acute illness.
Rare priapism has been reported with alpha-1 blockers; counsel patients to seek urgent care for prolonged erections.

Drug Interactions

Additive hypotension with other antihypertensives, nitrates, or PDE5 inhibitors (sildenafil/tadalafil)—avoid risky combinations and separate dosing when possible. Antipsychotics with orthostatic liability (clozapine, quetiapine) can compound dizziness and falls—start even lower and monitor closely.

Alcohol, sedatives, and dehydration can compound dizziness and syncope; provide harm-reduction counseling and reassess during intercurrent illness.

Practice Notes

Define the target symptom (nightmares, sleep maintenance, daytime hyperarousal) and document a titration and reassessment plan. Pair with PTSD-first-line treatments (trauma-focused psychotherapy, SSRIs/SNRIs) and sleep interventions; avoid treating prazosin as a standalone PTSD strategy.

If the response is unclear after a reasonable titration window, taper and discontinue rather than continuing indefinitely.

References

Prazosin hydrochloride prescribing information — DailyMed (2025)
Trial OF Prazosin FOR Post Traumatic Stress Disorder IN Military Veterans — The New England Journal of Medicine (2018)
Prazosin FOR Treatment OF Post Traumatic Stress Disorder — CNS Spectrums (2021)
Treatment Guidelines for PTSD — Journal of Clinical Medicine (2021)