Prazosin HCl, a quinazoline derivative, is the first of a new chemical class of antihypertensive and a class of medications called alpha-blockers. It works by relaxing the blood vessels so that blood can flow more easily through the body.


Hypertension: Prazosin hydrochloride Tablets are indicated for the treatment of hypertension, to lower blood pressure.
Note: It can be used alone or in combination with other medications to help lower your blood pressure.
Benign Prostatic Hyperplasia (BPH): Prazosin hydrochloride is indicated as an adjunct in the symptomatic treatment of urinary obstruction caused by benign prostatic hyperplasia. It is also of value to patients awaiting prostatic surgery.


Mechanism of Action:
Prazosin belongs to a class of drugs called alpha-blockers. A class of drugs is a group of medications that work similarly. These drugs are often used to treat similar conditions. Your blood pressure can increase when your blood vessels constrict and get narrower. Prazosin works by relaxing your blood vessels so that blood will flow more easily through them.
This helps make your blood pressure decrease.

Absorption: Orally. The oral bioavailability of prazosin ranges from 43.5 to 69.3% (mean 56.9%)
Protein binding: 80% - 90%
Metabolism: metabolized by the liver
Excretion: This drug is mainly excreted in the bile and the feces

Side Effects:

● Dizziness
● Drowsiness
● Lightheadedness
● Headache
● Lack of energy
● Weakness
● Nausea
● Fever
If these effects are mild, they may disappear within a few days or a couple of weeks. If they're more severe or don't disappear, talk to your doctor or pharmacist.


Prazosin hydrochloride is contraindicated in patients with known sensitivity to quinazolines, prazosin hydrochloride, or any of the inert ingredients.

Drug Interaction:

● Cardiac glycosides-digitalis and digoxin
● Hypoglycemics-insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide
● Tranquilizers and sedatives- chlordiazepoxide, diazepam, and phenobarbital
● Analgesics, antipyretics, and anti-inflammatories-propoxyphene, aspirin, indomethacin, and phenylbutazone

Warning & Precautions:

Pregnancy: Speak with your doctor if you're pregnant or planning to become pregnant. Prazosin should be used during pregnancy only if the potential benefit justifies the potential risk.
Breast-feeding:Prazosin passes through breast milk. Talk to your doctor before breastfeeding while taking prazosin.
Effects on Ability to Drive and Use Machines: Prazosin oral capsule may cause dizziness and drowsiness after your first dose. Avoid driving or performing any hazardous tasks for the first 24 hours after taking this medication or when your dose is increased.


Prazosin hydrochloride can be taken with or without food. The tablets could be swallowed whole with a sufficient amount of liquid. Patients should not chew, divide, or crush the tablets
OR As Directed by the Physician.
If you miss a dose of Prazosin Tablets, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular schedule.
Do not double the dose.

Storage Instructions:
Store in a cool, dry & dark place. It is protected from direct sunlight.