Summary

Commonly reported side effects of prazosin include: dizziness. Other side effects include: syncope and drowsiness. Continue reading for a comprehensive list of adverse effects.

Applies to prazosin: oral capsules.

Side effects include:

Dizziness, lightheadedness, headache, drowsiness, lack of energy, weakness, palpitation, nausea.

For Healthcare Professionals

Applies to prazosin: compounding powder, oral capsule.

General

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

Cardiovascular

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]

Other

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

Rare (less than 0.1%): Fever, pain

Frequency not reported: Malaise^[Ref]

Gastrointestinal

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]

Respiratory

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

Psychiatric

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

Uncommon (0.1% to 1%): Insomnia

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

Ocular

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]

Genitourinary

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

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

Dermatologic

Common (1% to 10%): Rash

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

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

Metabolic

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

Musculoskeletal

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

Immunologic

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

Endocrine

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

Hepatic

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