Prazosin hydrochloride, a quinazoline derivative, is the first of a new chemical class of antihypertensives. It is the hydrochloride salt of 1-(4-amino-6,7-dimethoxy- 2-quinazolinyl)-4-(2-furoyl) piperazine and its structural formula is: Molecular formula C19H21N5O4∙HCl It is a white, crystalline substance, slightly soluble in water and isotonic saline, and has a molecular weight of 419.87. Each 1 mg capsule of prazosin hydrochloride for oral use contains drug equivalent to 1 mg free base. Inert ingredients in the formulations are: hard gelatin capsules (which may contain Blue 1, Red 3, Red 28, Red 40, and other inert ingredients); magnesium stearate; sodium lauryl sulfate; starch; sucrose. Chemical Structure

What kind of drug is prazosin?

The FDA classifies prazosin as an alpha-adrenergic blocker. Alpha-adrenergic blockers block the alpha-1 receptors that adrenaline-like signals use to tighten muscle in blood vessels and the prostate. This relaxes those muscles, lowering blood pressure and easing urine flow in men with an enlarged prostate. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.

Can you take prazosin with other medicines?

It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run prazosin against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.

What brand names is prazosin sold under?

We track 2 prazosin-containing products in the U.S.: Minipress and Minipress XL. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.

What forms does prazosin come in?

Across the brands we track, prazosin is currently marketed as capsule and tablet, extended release, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Is there a generic prazosin?

We do not currently list a generic-labelled prazosin product. That does not always mean none exists — it means none appears under a generic name in the FDA data we track. Ask your pharmacist.

Has prazosin been recalled?

The FDA's Enforcement database lists at least 5 recall records whose product description mentions prazosin. The most recent: Prazosin Hydrochloride Capsules (Mar 27, 2026). A recall applies to specific lots, not to the drug as a whole — check the record for the affected lot numbers.

Prazosin: uses, dosing, side effects & brands

Prazosin is an alpha-adrenergic blocker sold in the U.S. under 2 brand and generic names, for hypertension, prostatic hyperplasia and raynaud disease. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.

By the pharmaranks editorial teamReviewed against the FDA (openFDA label, NDC Directory & Enforcement) sourcesHow we research

Key facts

Drug class: Alpha-Adrenergic Blocker
Treats: Hypertension, Prostatic Hyperplasia and Raynaud Disease
Available as: Capsule · Tablet, extended release
Sold as: 2 products — Minipress and Minipress XL
Prescription?: Prescription only
Generic available?: Not in our catalog
Typical price: about $3 for a 30-count supply

How prazosin is dosed

From the FDA label for Minipress (application NDA017442). Other prazosin products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.

The dose of prazosin hydrochloride capsules should be adjusted according to the patient's individual blood pressure response. The following is a guide to its administration: Initial Dose 1 mg two or three times a day (see WARNINGS .) Maintenance Dose Dosage may be slowly increased to a total daily dose of 20 mg given in divided doses. The therapeutic dosages most commonly employed have ranged from 6 mg to 15 mg daily given in divided doses. Doses higher than 20 mg usually do not increase efficacy, however a few patients may benefit from further increases up to a daily dose of 40 mg given in divided doses. After initial titration some patients can be maintained adequately on a twice daily dosage regimen. Use With Other Drugs When adding a diuretic or other antihypertensive agent, the dose of prazosin hydrochloride capsules should be reduced to 1 mg or 2 mg three times a day and retitration then carried out. Concomitant administration of prazosin hydrochloride capsules with a PDE-5 inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension; therefore, PDE-5 inhibitor therapy should be initiated at the lowest dose in patients taking prazosin hydrochloride capsules.

Prazosin side effects

Clinical trials were conducted on more than 900 patients. During these trials and subsequent marketing experience, the most frequent reactions associated with prazosin hydrochloride therapy are: dizziness 10.3%, headache 7.8%, drowsiness 7.6%, lack of energy 6.9%, weakness 6.5%, palpitations 5.3%, and nausea 4.9%. In most instances, side effects have disappeared with continued therapy or have been tolerated with no decrease in dose of drug. Less frequent adverse reactions which are reported to occur in 1–4% of patients are: Gastrointestinal: vomiting, diarrhea, constipation. Cardiovascular: edema, orthostatic hypotension, dyspnea, syncope. Central Nervous System: vertigo, depression, nervousness. Dermatologic: rash. Genitourinary: urinary frequency. EENT: blurred vision, reddened sclera, epistaxis, dry mouth, nasal congestion. In addition, fewer than 1% of patients have reported the following (in some instances, exact causal relationships have not been established): Gastrointestinal: abdominal discomfort and/or pain, liver function abnormalities, pancreatitis. Cardiovascular: tachycardia. Central Nervous System: paresthesia, hallucinations. Dermatologic: pruritus, alopecia, lichen planus. Genitourinary: incontinence, impotence, priapism. EENT: tinnitus. Other: diaphoresis, fever, positive ANA titer, arthralgia. Single reports of pigmentary mottling and serous retinopathy, and…

Every prazosin product we track (2)

Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.

Prazosin products
#	Drug	Rating	Type	Form	Generic?	Typical price
1	Minipress	56/100	Prescription	Capsule	Generic	$3	View →
2	Minipress XL	56/100	Prescription	Tablet	Generic

What prazosin pills look like

Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.

Prazosin pill imprints
Imprint	Strength	Colour	Shape	Maker
020;novitium	2 mg	brown	capsule	—
021;novitium	5 mg	blue, brown	capsule	—
PRA;5	5 mg	yellow, blue	capsule	—
020;novitium	2 mg	brown, brown	capsule	—
AC;540	1 mg	white	capsule	—
019;novitium	1 mg

Combination products containing prazosin

A combination is a different drug — different dosing, different warnings. It is listed here so you can find it, not so you can substitute it.

Minizide

Prazosin recalls

From the FDA Enforcement database. A recall covers specific lots — not the drug as a whole.

Frequently asked questions

What is prazosin?: Prazosin hydrochloride, a quinazoline derivative, is the first of a new chemical class of antihypertensives. It is the hydrochloride salt of 1-(4-amino-6,7-dimethoxy- 2-quinazolinyl)-4-(2-furoyl) piperazine and its structural formula is: Molecular formula C19H21N5O4∙HCl It is a white, crystalline substance, slightly soluble in water and isotonic saline, and has a molecular weight of 419.87. Each 1 mg capsule of prazosin hydrochloride for oral use contains drug equivalent to 1 mg free base. Inert ingredients in the formulations are: hard gelatin capsules (which may contain Blue 1, Red 3, Red 28, Red 40, and other inert ingredients); magnesium stearate; sodium lauryl sulfate; starch; sucrose. Chemical Structure
What kind of drug is prazosin?: The FDA classifies prazosin as an alpha-adrenergic blocker. Alpha-adrenergic blockers block the alpha-1 receptors that adrenaline-like signals use to tighten muscle in blood vessels and the prostate. This relaxes those muscles, lowering blood pressure and easing urine flow in men with an enlarged prostate. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take prazosin with other medicines?: It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run prazosin against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is prazosin sold under?: We track 2 prazosin-containing products in the U.S.: Minipress and Minipress XL. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does prazosin come in?: Across the brands we track, prazosin is currently marketed as capsule and tablet, extended release, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.

Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.