Please check your internet connection and try again.
# Prazosin
## Overview
Prazosin is an alpha-1 adrenergic blocker used primarily for hypertension and off-label for nightmares associated with PTSD.
## Primary Indications
* Hypertension
* Symptomatic management of nightmares and sleep disturbances in patients with PTSD
## Adult Dosing
* **Hypertension:** Initiate at 1 mg orally twice daily. Increase dose gradually based on patient response and tolerability. Typical maintenance dose is 3-10 mg orally twice daily. Maximum dose is 20 mg orally twice daily.
* **PTSD Nightmares:** Initiate at 1 mg orally at bedtime. Increase dose as needed. Typical effective dose is 3-5 mg orally at bedtime, but doses up to 10 mg orally at bedtime have been used.
## Pediatric Dosing
Prazosin is not FDA-approved for pediatric use. Dosing in children for hypertension is extrapolated and should be guided by specialist consultation and institutional protocols. Available literature suggests starting doses of 0.1 mg/kg/day divided into two or three doses, not to exceed the adult maximum. Safety and efficacy for PTSD nightmares in children are not established.
## Dose Adjustments
* **Renal Impairment:** Use with caution. No specific dose adjustment guidelines are universally established, but reduced dosage may be warranted in severe impairment.
* **Hepatic Impairment:** No specific dose adjustment guidelines. Use with caution.
## Contraindications
* Hypersensitivity to prazosin or other quinazoline derivatives.
## Adverse Effects
* **Common:** Dizziness, lightheadedness, headache, drowsiness, orthostatic hypotension, palpitations, nausea.
* **Serious:** Syncope (especially with the first dose or dose increases), severe hypotension, priapism (rare).
## Key Drug Interactions
* **Antihypertensives:** Additive hypotensive effect, increasing the risk of orthostatic hypotension.
* **Beta-blockers:** May exacerbate orthostatic hypotension, especially during initiation.
* **Diuretics:** Additive hypotensive effect.
## Monitoring
* Blood pressure (sitting and standing) before and after dose initiation and titration.
* Signs and symptoms of orthostatic hypotension.
* For PTSD: Monitor the frequency and severity of nightmares and sleep disturbances.
## Clinical Pearls
* The first-dose phenomenon (marked orthostatic hypotension and syncope) can occur with the initial dose or with rapid dose increases. Advise patients to take the first dose at bedtime and avoid driving or hazardous activities until they know how the medication affects them.
* Dosing should be titrated slowly and individually to minimize orthostatic effects.
* For PTSD, consider that therapeutic effects may take several weeks to become apparent.
*Please consult current prescribing information for the most up-to-date and complete drug information.*
