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Tamsulosin Hydrochloride


Pronunciation: tam-SOO-loe-sin HIGH-droe-KLOR-ide
Class: Alpha-1-adrenergic blocker

Trade Names

- Capsules 0.4 mg

Novo-Tamsulosin (Canada)
Sandoz Tamsulosin (Canada)


Selectively blocks alpha 1 -adrenergic receptors causing relaxation of prostate smooth muscle resulting in an increase in urinary flow rate and a reduction in symptoms of benign prostatic hypertrophy.

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Tamsulosin absorption is greater than 90% (fasting), and T max is 4 to 5 h (fasting) and 6 to 7 h (with food). Taking tamsulosin under fasted conditions results in a 30% increase in bioavailability (AUC) and 40% to 70% increase in peak concentrations.


Steady state is achieved by the fifth day of every day dosing. Vd is about 16 L. Tamsulosin is widely distributed to most tissues, including kidney, prostate, liver, gall bladder, heart, aorta, and brown fat. There is minimal distribution to brain, spinal cord, and testes. The drug is 94% to 99% protein bound.


Tamsulosin is extensively metabolized by CYP-450 in the liver.


Tamsulosin t ½ is 5 to 7 h. Approximately 10% is excreted unchanged in urine.

Special Populations


AUC is 40% higher in subjects 55 to 75 yr of age compared with subjects 20 to 32 yr of age.

Indications and Usage

Treatment of signs and symptoms of benign prostatic hyperplasia.


Standard considerations.

Dosage and Administration


PO 0.4 mg/day, administered approximately 30 min following the same meal each day. If the patient fails to respond after 2 to 4 wk, the dose may be increased to 0.8 mg/day.


Store at controlled room temperature (59° to 86°F). Protect from excessive moisture.

Drug Interactions


Concomitant use may decrease tamsulosin Cl and increase the AUC. Use with caution.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Headache (21%); dizziness (17%); somnolence (4%); decreased libido (2%); insomnia (1%).


Rhinitis (18%); pharyngitis (5%); amblyopia (2%).


Diarrhea (6%); nausea (4%); tooth disorder (2%).


Abnormal ejaculation (18%).


Increased cough (5%); sinusitis (4%).


Infection (11%); asthenia (9%); back pain (8%); chest pain (4%).



Category B .


Not indicated for use in women.


Safety and efficacy not established.


Tamsulosin is currently not indicated for the treatment of hypertension.


Association is rare; can lead to permanent impotence if not properly treated.

Prostate cancer

Rule out before starting therapy.



Hypotension, severe headache.

Patient Information

  • Advise about the possibility of priapism, which requires immediate medical attention.
  • Advise patient to take prescribed dose every day, about 30 min after the same meal each day.
  • Advise patient not to crush, chew, or open capsule, and to swallow the capsule whole with a full glass of water.
  • Advise patient that dose may be increased after 2 to 4 wk to increase beneficial effects on the prostate gland. Caution patient that if a larger dose is being used and is interrupted for several days to restart therapy with the lower dose.
  • Caution patient to avoid sudden position changes to prevent orthostatic hypotension. If orthostatic hypotension does occur, instruct patient to sit or lie down.
  • Caution patient that drug may cause dizziness or drowsiness and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.
  • Instruct patient to report the following symptoms to the health care provider: dizziness, excessive drowsiness, fainting, sexual dysfunction.
  • Advise patient to contact health care provider if urinary symptoms do not improve or if they worsen while taking this medication.
  • Advise patient to read patient information leaflet before starting therapy and with each refill.

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