Description

Simple

A medication used to treat an enlarged prostate or certain types of kidney stones, and to help with difficulty urinating in women.

Clinical

An alpha-1A and alpha-1B adrenergic receptor antagonist used to treat benign prostatic hyperplasia, ureteral stones, prostatitis, and female voiding dysfunction.

Overview

Tamsulosin is a selective alpha-1A and alpha-1B adrenoceptor antagonist that exerts its greatest effect in the prostate and bladder, where these receptors are most common.[Label] It is indicated for the treatment of signs and symptoms of benign prostatic hypertrophy.[Label] Antagonism of these receptors leads to relaxation of smooth muscle in the prostate and detrusor muscles in the bladder, allowing for better urinary flow.[Label] Other alpha-1 adrenoceptor antagonists developed in the 1980s were less selective and more likely to act on the smooth muscle of blood vessels, resulting in hypotension.[5]

Tamsulosin was first approved by the FDA on April 15, 1997.[6]

Pharmacology

Indication

Tamsulosin is indicated for the treatment of signs and symptoms of benign prostatic hyperplasia.[Label]

Tamsulosin is also used off label for the treatment of ureteral stones, prostatitis, and female voiding dysfunction.[ Read more

Pharmacodynamic

Tamsulosin is an alpha adrenoceptor blocker with specificity for the alpha-1A and alpha-1D subtypes, which are more common in the prostate and submaxillary tissue.[ Read more

Mechanism of action

Tamsulosin is a blocker of alpha-1A and alpha-1D adrenoceptors.[Label, Read more

Absorption

Oral tamsulosin is 90% absorbed in fasted patients.[Label] The area under the curve is 151-199ng/mL\*hr for a 0.4mg oral dose and 440-557ng/mL*hr for a 0.8mg oral dose.[Label] The maximum plasma concentration is 3.1-5.3ng/mL for a 0.4mg oral dose and 2.5-3.6ng/mL for a 0.8mg oral dose.[Label] Taking... Read more

Protein binding

Tamsulosin is 94%-99% protein bound, mostly to alpha-1-acid glycoprotein.[Label]

Volume of distribution

16L after intravenous administration.[Label]

Clearance

2.88L/h.[Label]

Half life

The half life in fasted patients is 14.9±3.9 hours.[Label] The elimination half life is 5-7 hours and the apparent half life is 9 to 13 hours in healthy subjects.[Label] In patients who require tamsulosin, the apparent half life is 14-15 hours.[Label]

Route of elimination

97% of an orally administered does is recovered in studies, which 76% in the urine and 21% in the feces after 168 hours.[Label] 8.7% of the dose is excreted as unmetabolized tamsulosin.[Label, Read more

Toxicity

In the event of overdose, patients may experience hypotension and should lie down in a supine position to maintain blood pressure and heart rate.[Label] If further measures are required intravenous fluids should be considered.[Label] If further progression is required, vasopressors may be used and r... Read more

Adverse Effects

Effect Regions Age Groups Incidences Evidence Type
Headache US
  • Kind: experimental
    • Percent: 19.3-21.1%
  • Kind: placebo
    • Percent: 20.1%
  • Clinical Trial
    Positive orthostatic test result US
  • Kind: experimental
    • Percent: 16-19%
  • Kind: placebo
    • Percent: 11%
  • Clinical Trial
    Abnormal ejaculation US
  • Kind: experimental
    • Percent: 8.4-18.1%
  • Kind: placebo
    • Percent: 0.2%
  • Clinical Trial
    Rhinitis US
  • Kind: experimental
    • Percent: 13.1-17.9%
  • Kind: placebo
    • Percent: 8.3%
  • Clinical Trial
    Dizziness US
  • Kind: experimental
    • Percent: 14.9-17.1%
  • Kind: placebo
    • Percent: 10.1%
  • Clinical Trial
    Infection US
  • Kind: experimental
    • Percent: 9.0-10.8%
  • Kind: placebo
    • Percent: 7.5%
  • Clinical Trial
    Asthenia US
  • Kind: experimental
    • Percent: 7.8-8.5%
  • Kind: placebo
    • Percent: 5.5%
  • Clinical Trial
    Back Pain US
  • Kind: experimental
    • Percent: 7.0-8.3%
  • Kind: placebo
    • Percent: 5.5%
  • Clinical Trial
    Diarrhea US
  • Kind: experimental
    • Percent: 4.3-6.2%
  • Kind: placebo
    • Percent: 4.5%
  • Clinical Trial
    Pharyngitis US
  • Kind: experimental
    • Percent: 5.1-5.8%
  • Kind: placebo
    • Percent: 4.7%
  • Clinical Trial
    Increased cough US
  • Kind: experimental
    • Percent: 3.4-4.5%
  • Kind: placebo
    • Percent: 2.4%
  • Clinical Trial
    Somnolence US
  • Kind: experimental
    • Percent: 3.0-4.3%
  • Kind: placebo
    • Percent: 1.6%
  • Clinical Trial
    Chest Pain US
  • Kind: experimental
    • Percent: 4.0-4.1%
  • Kind: placebo
    • Percent: 3.7%
  • Clinical Trial
    Nausea US
  • Kind: experimental
    • Percent: 2.6-3.9%
  • Kind: placebo
    • Percent: 3.2%
  • Clinical Trial
    Sinusitis US
  • Kind: experimental
    • Percent: 2.2-3.7%
  • Kind: placebo
    • Percent: 1.6%
  • Clinical Trial
    Insomnia US
  • Kind: experimental
    • Percent: 1.4-2.4%
  • Kind: placebo
    • Percent: 0.6%
  • Clinical Trial
    Decreased libido US
  • Kind: experimental
    • Percent: 1.0-2.0%
  • Kind: placebo
    • Percent: 1.2%
  • Clinical Trial
    Tooth disorder US
  • Kind: experimental
    • Percent: 1.2-2.0%
  • Kind: placebo
    • Percent: 1.4%
  • Clinical Trial
    Blurred vision US
  • Kind: experimental
    • Percent: 0.2-2.0%
  • Kind: placebo
    • Percent: 0.4%
  • Clinical Trial
    Postural Hypotension US
  • Kind: experimental
    • Percent: 0.2-0.4%
  • Kind: placebo
    • Percent: 0%
  • Clinical Trial
    Dry Eyes US
    Literature
    Palpitations US
    Post Marketing
    Hypotension US
    Post Marketing
    Atrial Fibrillation US
    Post Marketing
    Arrhythmia US
    Post Marketing
    Tachycardia US
    Post Marketing
    Skin desquamation US
    Post Marketing
    Stevens-Johnson Syndrome US
    Post Marketing
    Erythema multiforme US
    Post Marketing
    Dermatitis exfoliative US
    Post Marketing
    Constipation US
    Post Marketing
    Vomiting US
    Post Marketing
    Dry Mouth US
    Post Marketing
    Visual Impairment US
    Post Marketing
    Epistaxis US
    Post Marketing
    Intaoperative floppy iris syndrome US
    Post Marketing
    Skin Rash US
    Post Marketing
    Pruritus US
    Post Marketing
    Urticaria US
    Post Marketing
    Allergic-type respiratory symptoms US
    Post Marketing
    Angioedema US
    Post Marketing
    Dyspnea US
    Post Marketing
    Priapism US
    Post Marketing
    Intaoperative floppy iris syndrome US
    Post Marketing

    Contraindications

    • Route:
      • Oral
    • Dose Form:
      • Capsule
    • Hypersensitivity:
      • true
    • Sex Group: all
    • Regions: US

    Food Interactions

    Take after a meal. Take 30 minutes after the same meal each day to reduce plasma level variations.