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Tamsulosin Side Effects

Medically reviewed by Last updated on May 30, 2023.

Applies to tamsulosin: oral capsule.

Serious side effects of Tamsulosin

Along with its needed effects, tamsulosin 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 tamsulosin:

More common

  • Cough or hoarseness
  • fever or chills
  • lower back or side pain
  • painful or difficult urination

Less common

  • Chest pain


  • Dizziness or lightheadedness
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • fainting
  • feeling of constant movement of self or surroundings
  • painful or prolonged erection of the penis
  • sensation of spinning

Incidence not known

  • Blistering, peeling, or loosening of the skin
  • blurred vision
  • confusion
  • diarrhea
  • difficult or labored breathing
  • fast, pounding, or irregular heartbeat or pulse
  • itching
  • joint or muscle pain
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • sweating
  • tightness of the chest
  • unusual tiredness or weakness

Other side effects of Tamsulosin

Some side effects of tamsulosin 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

  • Abnormal ejaculation
  • back pain
  • body aches or pain
  • congestion
  • headache
  • lack or loss of strength
  • sneezing
  • stuffy or runny nose
  • tender, swollen glands in the neck
  • trouble swallowing
  • voice changes

Less common

  • Decreased interest in sexual intercourse
  • decreased sexual drive or performance
  • drowsiness
  • inability to have or keep an erection
  • increased cough
  • loss in sexual ability, desire, drive, or performance
  • nausea
  • pain or tenderness around the eyes and cheekbones
  • sleepiness or unusual drowsiness
  • tooth disorder
  • trouble sleeping

Incidence not known

  • Constipation
  • hives or welts, skin rash
  • redness of the skin
  • vomiting

For Healthcare Professionals

Applies to tamsulosin: oral capsule.


The most commonly reported side effects were abnormal ejaculation, influenza-like symptoms, headache, dizziness, and rhinitis.[Ref]


Very common (10% or more): Infection (up to 10.8%)

Uncommon (0.1% to 1%): Flu like symptoms

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


Common (1% to 10%): Chest pain

Uncommon (0.1% to 1%): Orthostatic hypotension

Rare (less than 0.1%): Syncope

Postmarketing reports: Palpitations, hypotension, atrial fibrillation, arrhythmia, tachycardia[Ref]


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

Postmarketing reports: Stevens-Johnson syndrome, erythema multiforme, exfoliative dermatitis, skin desquamation[Ref]

Nervous system

Very common (10% or more): Headache (21%), dizziness (17%)

Common (1% to 10%): Somnolence, insomnia

Frequency not reported: Vertigo[Ref]


Very common (10% or more): Abnormal ejaculation (18%)

Common (1% to 10%): Ejaculation disorders (e.g., retrograde ejaculation, ejaculation failure), decreased libido

Uncommon (0.1% to 1%): Semen volume reduced, ejaculation delayed

Postmarketing reports: Priapism[Ref]


Very common (10% or more): Rhinitis (up to 17.9%)

Common (1% to 10%): Pharyngitis, Increased cough, sinusitis

Uncommon (0.1% to 1%): Nasal congestion

Postmarketing reports: Dyspnea, epistaxis[Ref]


Common (1% to 10%): Back pain[Ref]


Common (1% to 10%): Diarrhea, nausea, tooth disorder

Uncommon (0.1% to 1%): Constipation, vomiting

Frequency not reported: Dry mouth[Ref]


Common (1% to 10%): Blurred vision

Postmarketing reports: Visual impairment, intraoperative Floppy Iris Syndrome (IFIS)[Ref]


Common (1% to 10%): Asthenia

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


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


1. Product Information. Flomax (tamsulosin). Boehringer-Ingelheim. 2001.

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.