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) sourcesUpdated Jul 24, 2026How we research

Key facts

Drug class: Alpha-Adrenergic Blocker
Treats (across its forms): 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
What the pharmacy pays: about $3 for a 30-count supply — not your price

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How Minipress 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.

Everything below is the FDA label for Minipress (capsule). Prazosin is also sold as tablet, extended release, and those are different medicines to take — follow the label for the one you were prescribed.

Minipress 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…

Who shouldn’t take Minipress

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

Minipress drug interactions

Prazosin hydrochloride capsules have been administered without any adverse drug interaction in limited clinical experience to date with the following: (1) cardiac glycosides– digitalis and digoxin; (2) hypoglycemics–insulin, chlorpropamide, phenformin, tolazamide, and tolbutamide; (3) tranquilizers and sedatives–chlordiazepoxide, diazepam, and phenobarbital; (4) antigout–allopurinol, colchicine, and probenecid; (5) antiarrhythmics–procainamide, propranolol (see WARNINGS however), and quinidine; and (6) analgesics, antipyretics and anti-inflammatories–propoxyphene, aspirin, indomethacin, and phenylbutazone. Addition of a diuretic or other antihypertensive agent to prazosin hydrochloride capsules has been shown to cause an additive hypotensive effect. This effect can be minimized by reducing the prazosin hydrochloride dose to 1 to 2 mg three times a day, by introducing additional antihypertensive drugs cautiously, and then by retitrating prazosin hydrochloride based on clinical response. Concomitant administration of prazosin hydrochloride capsules with a phosphodiesterase-5 (PDE-5) inhibitor can result in additive blood pressure lowering effects and symptomatic hypotension (see DOSAGE AND ADMINISTRATION ).

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?	Pharmacy pays
1	Minipress	64/100	Prescription	Capsule	Generic	$3	View →
2	Minipress XL	64/100	Prescription	Tablet	Generic	$3	View →

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	green, brown	capsule	—

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.

How long prazosin keeps

No prazosin label we read sets a separate limit for after opening, but they do specify how it must be stored — and the stability behind any date assumes those conditions.

Does prazosin expire? The in-use limits and storage rules from its labels

Prazosin and breastfeeding

From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.

Because little is available on the use of prazosin during breastfeeding, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Full LactMed record for prazosin: levels in milk, effects in breastfed infants, and the drugs it would consider instead

National Institute of Child Health and Human Development, record revised December 15, 2024. LactMed states its information is not a substitute for professional judgement.

What people report to the FDA about prazosin

The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 1,345 reports naming prazosin, and the FDA flagged 65% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:

fatigue109 reports
abdominal pain95 reports
nausea84 reports
diarrhoea70 reports
headache69 reports
dyspnoea67 reports
hypotension62 reports
renal impairment61 reports

Read these as a signal, not a rate. A report does not mean prazosin caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.

Source: openFDA drug/event (FAERS), retrieved July 26, 2026.

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Frequently asked questions

What is Minipress?

Prazosin hydrochloride, a quinazoline derivative, is the first of a new chemical class of antihypertensives.

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.

Cite this page

APA: pharmaranks. (2026, July 24). Prazosin: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/prazosin
MLA: “Prazosin: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/prazosin.

We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.

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.

Read the full FDA label for prazosin on DailyMed (NIH) ↗.