Skip to main content

Terazosin Side Effects

Medically reviewed by Last updated on May 10, 2022.


Commonly reported side effects of terazosin include: dizziness. Other side effects include: asthenia, headache, and peripheral edema. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to terazosin: oral capsule

Side effects requiring immediate medical attention

Along with its needed effects, terazosin 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 as soon as possible if any of the following side effects occur while taking terazosin:

More common

Less common

  • Chest pain
  • dizziness or lightheadedness when getting up from a lying or sitting position
  • fainting (sudden)
  • fast or irregular heartbeat
  • pounding heartbeat
  • shortness of breath
  • swelling of feet or lower legs


  • Weight gain

Side effects not requiring immediate medical attention

Some side effects of terazosin 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

  • Headache
  • unusual tiredness or weakness

Less common

For Healthcare Professionals

Applies to terazosin: oral capsule, oral tablet


Asthenia, blurred vision, dizziness, impotence, nasal congestion/rhinitis, nausea, somnolence, palpitations, peripheral edema, and postural hypotension were significantly more common (p-value less than or equal to 0.05) in patients receiving this drug than in patients receiving placebo.[Ref]

Nervous system

Very common (10% or more): Dizziness (up to 19.3%), headache (up to 16.2%)

Common (1% to 10%): Syncope, somnolence, paresthesia[Ref]


Very common (10% or more): Asthenia (up to 11.3%)

Common (1% to 10%): Flu syndrome, vertigo, peripheral edema

Uncommon (0.1% to 1%): Edema

Frequency not reported: Chest pain, facial edema, fever, cold symptoms, flu symptoms, tinnitus[Ref]


Common (1% to 10%): Postural hypotension, palpitations, tachycardia

Uncommon (0.1% to 1%): Hypotension

Frequency not reported: Arrhythmia, vasodilation

Postmarketing reports: Atrial fibrillation[Ref]


Common (1% to 10%): Dyspnea, nasal congestion/rhinitis, sinusitis

Frequency not reported: Bronchitis, epistaxis, cough increased, pharyngitis[Ref]


Common (1% to 10%): Back pain, pain-extremities

Frequency not reported: Neck pain, shoulder pain, arthralgia, arthritis, joint disorder, myalgia[Ref]


Common (1% to 10%): Impotence, urinary tract infection

Frequency not reported: Urinary frequency, urinary incontinence

Postmarketing reports: Priapism[Ref]


Common (1% to 10%): Nervousness

Uncommon (0.1% to 1%): Depression, libido decreased

Frequency not reported: Anxiety, insomnia[Ref]


Common (1% to 10%): Nausea

Frequency not reported: Abdominal pain, constipation, diarrhea, dry mouth, dyspepsia, flatulence, vomiting[Ref]


Common (1% to 10%): Blurred vision/amblyopia

Frequency not reported: Vision abnormal, conjunctivitis[Ref]


Uncommon (0.1% to 1%): Weight gain

Frequency not reported: Gout[Ref]


Frequency not reported: Pruritus, rash, sweating[Ref]


Postmarketing reports: Allergic reactions, anaphylaxis[Ref]


Postmarketing reports: Thrombocytopenia[Ref]


1. "Product Information. Hytrin (terazosin)." Abbott Pharmaceutical (2001):

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.