ATC Code G04CA02
Formula C20H28N2O5S
Molar Mass (g·mol−1) 408,51
Physical State solid
Melting Point (°C) 228–230
CAS Number 106133-20-4
PUB Number 129211
Drugbank ID DB00706
Solubility sparingly soluble in water


Tamsulosin is a drug used to treat symptomatic benign prostatic hyperplasia (BPH) and chronic prostatitis, as well as to aid in the passage of kidney stones. Strictly speaking, the drug is an alpha-1A and alpha-1D adrenoreceptor antagonist. Tamsulosin is taken by mouth.

Tamsulosin was approved for medical use in the United States in 1997.



Tamsulosin is an alpha-adrenoceptor blocker with high specificity for the alpha-1A and alpha-1D subtypes, which are particularly abundant in the prostate and submaxillary tissues. Blockade of these adrenoceptors relaxes smooth muscle in the prostate and improves urinary flow. Blockade of alpha-1D adrenoceptors relaxes the detrusor muscles of the bladder, preventing symptoms of congestion. The specificity of tamsulosin concentrates the effect in the target area and minimizes effects in areas such as the aorta.


Orally ingested tamsulosin is 90% absorbed. Time from ingestion to maximum plasma concentration is 4-7 hours. Tamsulosin is 94%-99% bound to proteins, mainly to the acidic alpha-1-glycoprotein. Tamsulosin is metabolized primarily in the liver by cytochrome P450 enzymes, mainly CYP-3A4 and -2D6. The plasma half-life in fasting patients is approximately 14 hours.


Side effects

Common side effects are:

  • Dizziness
  • headache
  • Insomnia
  • nausea
  • blurred vision
  • sexual dysfunction

Other less common side effects may include dizziness when standing and angioedema.

Toxicological data

LD50, rat, oral: 650 mg/kg

Markus Falkenstätter

Markus Falkenstätter

Markus Falkenstätter ist Autor zu pharmazeutischen Themen in der Medizin-Redaktion von Medikamio. Er befindet sich im letzten Semester seines Pharmaziestudiums an der Universität Wien und liebt das wissenschaftliche Arbeiten im Bereich der Naturwissenschaften.

Mag. pharm Stefanie Lehenauer

Mag. pharm Stefanie Lehenauer

Stefanie Lehenauer ist seit 2020 freie Autorin bei Medikamio und studierte Pharmazie an der Universität Wien. Sie arbeitet als Apothekerin in Wien und ihre Leidenschaft sind pflanzliche Arzneimittel und deren Wirkung.

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