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Minipress Side Effects

Generic name: prazosin

Medically reviewed by Last updated on Mar 29, 2024.

Note: This document contains side effect information about prazosin. Some dosage forms listed on this page may not apply to the brand name Minipress.

Applies to prazosin: oral capsule.

Serious side effects of Minipress

Along with its needed effects, prazosin (the active ingredient contained in Minipress) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking prazosin:

More common

Less common


Incidence not known

Other side effects of Minipress

Some side effects of prazosin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common


Incidence not known

For Healthcare Professionals

Applies to prazosin: compounding powder, oral capsule.


The most common adverse reactions were postural hypotension, dizziness, headache, drowsiness, lack of energy, weakness, palpitations, and nausea.[Ref]


Very common (10% or more): Postural hypotension (up to 14%)

Common (1% to 10%): Palpitations, tachycardia, orthostatic hypotension

Uncommon (0.1% to 1%): Angina pectoris

Rare (less than 0.1%): Bradycardia, flushing, hypotension, vasculitis

Frequency not reported: Angina exacerbation, myocardial infarction[Ref]

Nervous system

Very common (10% or more): Dizziness (up to 10.3%)

Common (1% to 10%): Drowsiness, headache, faintness, syncope, vertigo

Uncommon (0.1% to 1%): Paresthesia, tinnitus

Rare (less than 0.1%): Narcolepsy worsened[Ref]


Common (1% to 10%): Lack of energy, weakness, asthenia

Rare (less than 0.1%): Fever, pain

Frequency not reported: Malaise[Ref]


Common (1% to 10%): Constipation, diarrhea, dry mouth, nausea, vomiting

Uncommon (0.1% to 1%): Abdominal discomfort and/or pain

Rare (less than 0.1%): Pancreatitis[Ref]


Common (1% to 10%): Dyspnea, nasal congestion, epistaxis[Ref]


Common (1% to 10%): Depression, nervousness

Uncommon (0.1% to 1%): Insomnia

Rare (less than 0.1%): Hallucinations[Ref]


Common (1% to 10%): Blurred vision, sclera reddened

Uncommon (0.1% to 1%): Eye pain

Frequency not reported: Pigmentary mottling, serious retinopathy, cataract development, cataract disappearance[Ref]


Common (1% to 10%): Urinary frequency, impotence

Rare (less than 0.1%): Incontinence, priapism[Ref]


Common (1% to 10%): Rash

Uncommon (0.1% to 1%): Diaphoresis, pruritus, urticaria

Rare (less than 0.1%): Alopecia, lichen planus[Ref]


Common (1% to 10%): Edema[Ref]


Uncommon (0.1% to 1%): Arthralgia[Ref]


Rare (less than 0.1%): Allergic reaction, positive antinuclear antibody titer[Ref]


Rare (less than 0.1%): Gynecomastia[Ref]


Rare (less than 0.1%): Liver function abnormalities[Ref]


1. (2001) "Product Information. Minipress (prazosin)." Pfizer U.S. Pharmaceuticals

2. Cerner Multum, Inc. "UK Summary of Product Characteristics."

3. Cerner Multum, Inc. "Australian Product Information."

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.