Prazosin Hydrochloride: Brands, Price & Uses in Bangladesh

Prazosin Hydrochloride is an alpha-1 adrenergic receptor antagonist used mainly for blood pressure control, with additional guideline-supported and off-label uses described below.

Established / Approved Use

• Hypertension – Prazosin Hydrochloride is indicated for the treatment of high blood pressure, used alone or in combination with other antihypertensive agents (such as a diuretic), to lower blood pressure and reduce the risk of fatal and non-fatal cardiovascular events, primarily stroke and heart attack.

Guideline-Supported / Adjunct Uses

• Raynaud’s phenomenon – Prazosin Hydrochloride is used as an adjunct to reduce the frequency and severity of vasospastic attacks in Raynaud’s phenomenon/disease.
• Symptomatic benign prostatic hyperplasia (BPH) – Prazosin Hydrochloride may be used to relax smooth muscle in the prostate and bladder neck, improving urinary flow symptoms, generally as an adjunct/alternative when other alpha-blockers are unsuitable.
• Adjunct in congestive heart failure – Prazosin Hydrochloride has historically been used as an add-on vasodilator in selected patients with heart failure who cannot tolerate other therapies, although it is not considered a first-line heart-failure agent by current guidelines.

Off-Label Use (Evidence Mixed)

Trauma-related nightmares in post-traumatic stress disorder (PTSD) – Prazosin Hydrochloride has been used off-label, at bedtime, to reduce nightmares and improve sleep in patients with PTSD. Earlier controlled trials and some clinical guidelines supported this use; however, a large randomized trial found no significant benefit over placebo, so current guidance is mixed. Any use of Prazosin Hydrochloride for this purpose should be individualized and supervised by a physician.

The dose of Prazosin Hydrochloride must be individualized by indication and titrated slowly to minimize the risk of first-dose orthostatic hypotension and syncope. The very first dose of Prazosin Hydrochloride should be small (commonly 0.5–1 mg) and taken at bedtime, with the patient advised to avoid activities requiring alertness (e.g. driving) for several hours after the first dose or any dose increase.

Hypertension (Adults)

Raynaud’s Phenomenon (Adjunct)

Initial 0.5 mg twice daily, increased gradually as tolerated to a usual maintenance of 1–2 mg twice daily (up to 2 mg three times daily in some patients), under physician guidance.

Benign Prostatic Hyperplasia (Symptomatic, Adjunct/Alternative)

Initial 0.5 mg twice daily, increased as needed to a usual maintenance of about 2 mg twice daily (maximum around 4 mg/day), with blood pressure monitored given the risk of hypotension, especially in elderly patients.

PTSD-Related Nightmares (Off-Label, Evidence Mixed)

Typically initiated at 1 mg at bedtime and titrated slowly over weeks under psychiatric/medical supervision, based on response and tolerability; there is no single universally agreed dose, and response to Prazosin Hydrochloride for this use varies between patients.

Adverse effects of Prazosin Hydrochloride are generally dose-related and most prominent at the start of therapy or after a dose increase.

Common

• Dizziness
• Headache
• Drowsiness/sedation
• Lack of energy/weakness
• Palpitations
• Nausea

Less Common

• Orthostatic (postural) hypotension
• Fluid retention/edema
• Blurred vision
• Dry mouth, nasal congestion
• Vomiting, diarrhea, or constipation

Rare but Serious

• Syncope (“first-dose phenomenon”) – see Precautions and Warnings.
• Priapism (prolonged, painful erection) – see Precautions and Warnings.
• Intraoperative floppy iris syndrome during cataract surgery – see Precautions and Warnings.