[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Alpha blockers](https://durgical.com/en/pharmacology/classes/alpha-blockers/) › Tamsulosin [Pharmacology](https://durgical.com/en/pharmacology/) · [Alpha blockers](https://durgical.com/en/pharmacology/classes/alpha-blockers/) # Tamsulosin An alpha-1A blocker that relaxes the prostate and bladder neck so urine flows more easily in benign prostatic hyperplasia. It is not used for hypertension. Updated 2026-11-01 - Class: [Alpha blockers](https://durgical.com/en/pharmacology/classes/alpha-blockers/) - Receptor: Alpha-1A adrenergic receptor - ATC code: G04CA02 ◎**Alpha-1A adrenergic receptor**Tamsulosin ⓘ The figure shows tamsulosin bound to the human alpha-1A adrenergic receptor (cryo-EM structure with a nanobody). **Target in 3D:** Alpha-1A adrenergic receptor. PDB structure 7YMJ (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/7YMJ) · Drag to rotate · pinch to zoom ## Mechanism of action Tamsulosin blocks alpha-1A (and alpha-1D) receptors more than the alpha-1B subtype. Alpha-1A receptors predominate in the smooth muscle of the prostate, prostatic capsule and bladder neck; relaxing it reduces the dynamic obstruction to urine flow. Its smaller effect on vascular receptors means less fall in blood pressure than with other alpha-1 blockers. - Tamsulosin blocks alpha-1A receptors in the prostate and bladder neck - Prostatic smooth muscle relaxes - Urine flows more easily; blood pressure changes little ## Pharmacokinetics **Absorption** Oral, as modified-release capsules; well absorbed **Metabolism** Liver, by CYP3A4 and CYP2D6 **Elimination** Metabolites conjugated and excreted in urine **Half-life** About 9 to 13 hours in healthy volunteers and 14 to 15 hours in the target population (label) ## Indications - Signs and symptoms of benign prostatic hyperplasia [Benign prostatic hyperplasia →](https://durgical.com/en/conditions/benign-prostatic-hyperplasia/) - Other uses: kidney stones [Kidney stones (urolithiasis) →](https://durgical.com/en/conditions/kidney-stones/) ## Adverse effects ### Common - Dizziness on standing - Abnormal ejaculation (reduced, absent or retrograde) - Runny or stuffy nose - Sleepiness or trouble sleeping - Weakness and back pain ### Serious (rare, important) - Orthostatic hypotension and syncope - Priapism - Intraoperative floppy iris syndrome during cataract or glaucoma surgery - Allergic reactions, rarely in people with a serious sulfa allergy ## Contraindications - Hypersensitivity to tamsulosin or any component ## Key interactions **Strong CYP3A4 inhibitors (for example ketoconazole)** Much higher tamsulosin levels: the combination is avoided **CYP2D6 inhibitors (for example paroxetine) and moderate CYP3A4 inhibitors** Higher levels; used with caution **PDE-5 inhibitors** Additive fall in blood pressure ## What is monitored - Urinary symptoms and flow - Blood pressure lying and standing - Prostate cancer is excluded before and periodically during treatment ## Nursing care - Warn about dizziness and fainting, especially at the start or when treatment restarts after a break. - Before cataract or glaucoma surgery, tell the eye surgeon about tamsulosin use. - An erection lasting several hours is an emergency. - Ask about sulfa allergy before the first dose. ## Pregnancy and breastfeeding Tamsulosin is not indicated for women. ## Memory aid TAMSUlosin: Targets the prostate's Alpha-1A, Minimal Systemic (blood pressure) Upset. ## Test yourself Think of the answer, then tap the question to see it. ## Why does tamsulosin lower blood pressure less than prazosin? It has higher affinity for alpha-1A receptors, which predominate in prostatic smooth muscle, than for the vascular subtypes. ## What should a patient on tamsulosin tell the eye surgeon before cataract surgery? That they take an alpha-1 blocker, because of the risk of intraoperative floppy iris syndrome. ## Which antifungal must not be combined with tamsulosin, and why? Ketoconazole, a strong CYP3A4 inhibitor, which greatly raises tamsulosin levels. ## Which ejaculatory problem is typical of tamsulosin? Abnormal ejaculation: reduced, absent or retrograde ejaculation. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/tamsulosin/) ## Related drugs - [Prazosin](https://durgical.com/en/pharmacology/prazosin/) - [Doxazosin](https://durgical.com/en/pharmacology/doxazosin/) - [Terazosin](https://durgical.com/en/pharmacology/terazosin/) ## Related conditions - [Benign prostatic hyperplasia](https://durgical.com/en/conditions/benign-prostatic-hyperplasia/) - [Kidney stones (urolithiasis)](https://durgical.com/en/conditions/kidney-stones/) [← Back to the class: Alpha blockers](https://durgical.com/en/pharmacology/classes/alpha-blockers/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - TAMSULOSIN HYDROCHLORIDE capsule](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=13a5032d-0be1-4001-916e-459f0b1a051d) (DailyMed (U.S. National Library of Medicine), 2026); [Tamsulosin: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a698012.html) (MedlinePlus (U.S. National Library of Medicine), 2025); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=G04CA02) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Farmacología básica y clínica (Katzung), cap. 10 (McGraw Hill, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/tamsulosin/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/tamsulosin/