Tamsulosin

Overview

Tamsulosin, sold under the brand name Flomax among others, is a medication used to treat symptomatic benign prostatic hyperplasia and chronic prostatitis. It is also used to help with the passage of kidney stones. The evidence for benefit with a kidney stone is better when the stone is larger. Tamsulosin is taken by mouth.[1][2][3] WP

Common side effects include dizziness, headache, insomnia, nausea, blurry vision, and sexual problems. Other side effects may include feeling lightheaded with standing due to changes in blood pressure, and angioedema. Tamsulosin is an alpha blocker and works by relaxing muscles in the prostate. Specifically it is an α₁-adrenergic receptor blocker.[1][4][5] WP

Tamsulosin was approved for medical use in the United States in 1997. It is available as a generic medication. In 2023, it was the 24th most commonly prescribed medication in the United States, with more than 22 million prescriptions.[1][4][6][7][8] WP

Drug class

α1 blocker WP

From the Wikipedia article's infobox.

Uses, dosage and effects

Medical uses

Tamsulosin is used for benign prostatic hyperplasia and to help with the passage of kidney stones. Tamsulosin, however, appears to be effective for stones more than 4 mm and less than 10 mm only.[3][9] WP

Tamsulosin is also used as an add-on treatment for acute urinary retention. Men may void more successfully after catheter removal if they are taking tamsulosin, and are less likely to need repeat catheterization.[10] WP

Tamsulosin does not decrease the overall size of the prostate in men with benign prostatic hyperplasia and is not recommended for the prevention of prostate cancer.[11] WP

Combination therapy

The results of the CombAT (combination of dutasteride (Avodart) and tamsulosin (Duodart)) trial in 2008 demonstrated that treatment with the combination of dutasteride and tamsulosin provides greater symptom benefits compared to monotherapy with either agent alone for treatment of benign prostatic hyperplasia. The combination medication dutasteride/tamsulosin (Jalyn) was approved by the US Food and Drug Administration (FDA) in June 2010.[12][13] WP

Risks and side effects

Adverse effects

• Eyes: People taking tamsulosin are prone to a complication known as floppy iris syndrome during cataract surgery. Adverse outcomes of the surgery are greatly reduced by the surgeon's prior knowledge of the person's history with this drug, and thus having the option of alternative techniques.[14] WP
• Severe hypotension.[15][16] WP
• Alpha-blockers, including prazosin, terazosin, doxazosin, or tamsulosin, do not appear to affect all-cause mortality in heart failure rehospitalization in those also receiving β-blockers.[17] WP
• Tamsulosin can also cause retrograde ejaculation, which occurs when semen is redirected to the urinary bladder instead of being ejaculated normally. This is because tamsulosin relaxes the muscles of the urethral sphincters, which are normally closed during ejaculation.[18] WP

Pharmacology

Mechanism

Tamsulosin is a selective α₁ receptor antagonist that has preferential selectivity for the α1A receptor in the prostate versus the α1B receptor in the blood vessels.[19] WP

It may also have activity at the α1D receptor. WP

When alpha 1 receptors in the bladder neck, prostate, ureter, and urethra are blocked, a relaxation in smooth muscle tissue results. This mechanism decreases resistance to urinary flow, reduces discomfort associated with benign prostatic hyperplasia, and facilitates passage of kidney stones.[11] WP

Chemistry

Formula

C20H28N2O5S PC

CAS number

106133-20-4 PC

Molar mass (g/mol)

408.5 PC

IUPAC name (computed by PubChem)

5-[(2R)-2-[2-(2-ethoxyphenoxy)ethylamino]propyl]-2-methoxybenzenesulfonamide PC

SMILES

CCOC1=CC=CC=C1OCCN[C@H](C)CC2=CC(=C(C=C2)OC)S(=O)(=O)N PC

InChIKey

DRHKJLXJIQTDTD-OAHLLOKOSA-N PC

PubChem CID

129211

Harm reduction information

No harm reduction data is on file for this compound yet. That means no dose, timing or combination data from PsychonautWiki or TripSit. Please don't guess a dose from similar compounds. If you have taken it and feel unwell, contact emergency services or a poison control center.

User reports

Pop culture

No references added yet.

Sources

1. Other Tamsulosin Hydrochloride Monograph for Professionals
2. Other Prostatitis. 19 October 2017
3. Journal / agency Wang RC, Smith-Bindman R, Whitaker E, Neilson J, Allen IE, Stoller ML, Fahimi J. Effect of Tamsulosin on Stone Passage for Ureteral Stones: A Systematic Review and Meta-analysis. Annals of Emergency Medicine. March 2017. doi:10.1016/j.annemergmed.2016.06.044 · PMID 27616037
4. Other British national formulary: BNF 76. 2018
5. Other Hutchison LC, Sleeper RB. Fundamentals of Geriatric Pharmacotherapy: An Evidence-Based Approach. 2010
6. Other FDA Approves First Generic Tamsulosin to Treat Enlarged Prostate Gland. 2 March 2010
7. Other Top 300 of 2023
8. Other Tamsulosin Drug Usage Statistics, United States, 2014 - 2023
9. Other Study Shows Use of Tamsulosin or Nifedipine Helps Patients to Clear Ureteral Stone Fragments Faster and Reduces Rate of Recurrence
10. Journal / agency Lucas MG, Stephenson TP, Nargund V. Tamsulosin in the management of patients in acute urinary retention from benign prostatic hyperplasia. BJU International. February 2005. doi:10.1111/j.1464-410X.2005.05299.x · PMID 15679793
11. Other Lewis SM, Dirksen SR, Heitkemper MM, Bucher LH. Medical-surgical nursing: assessment and management of clinical problems. 2013
12. Journal / agency Roehrborn CG, Siami P, Barkin J, Damião R, Major-Walker K, Morrill B, Montorsi F. The effects of dutasteride, tamsulosin and combination therapy on lower urinary tract symptoms in men with benign prostatic hyperplasia and prostatic enlargement: 2-year results from the CombAT study. The Journal of Urology. February 2008. doi:10.1016/j.juro.2007.09.084 · PMID 18082216
13. Journal / agency Drug Approval Package: Jalyn (dutasteride and tamsulosin) NDA #022460. 3 February 2011
14. Other Taylor, Jill. Good Cataract Surgery Outcomes Possible in IFIS Due to Tamsulosin. 16 November 2006
15. Journal / agency Bird ST, Delaney JA, Brophy JM, Etminan M, Skeldon SC, Hartzema AG. Tamsulosin treatment for benign prostatic hyperplasia and risk of severe hypotension in men aged 40-85 years in the United States: risk window analyses using between and within patient methodology. BMJ. November 2013. doi:10.1136/bmj.f6320 · PMID 24192967 · PMC3817852
16. Journal / agency Ramirez J. Severe hypotension associated with α blocker tamsulosin. BMJ. November 2013. doi:10.1136/bmj.f6492 · PMID 24192968
17. Journal / agency Page RL, O'Bryant CL, Cheng D, Dow TJ, Ky B, Stein CM, Spencer AP, Trupp RJ, Lindenfeld J. Drugs That May Cause or Exacerbate Heart Failure: A Scientific Statement From the American Heart Association. Circulation. August 2016. doi:10.1161/CIR.0000000000000426 · PMID 27400984
18. Other Tamsulosin Side Effects
19. Other Shen H. Illustrated Pharmacology Memory Cards: PharMnemonics. 2008

Text and values on this page are quoted from Wikipedia (CC BY-SA 4.0), PubChem (public domain). Each value links to the exact revision it came from.