Description: Tamsulosin is a selective α1 adrenoreceptor-blocking agent that improves the urine flow rate and reduces symptoms in Benign Prostatic Hyperplasia (BPH). It works by relaxing the smooth muscles in the bladder neck and prostate by blocking their adrenoceptors.


Absorption: Completely absorbed from the GI tract. Peak plasma concentrations after 1 hr; 6 hr (modified-release preparation).

Distribution: Protein-binding: 99%.

Metabolism: Metabolised slowly in the liver primarily by CYP2D6 and CYP3A4.

Excretion: Excreted in urine (76%) and faeces (21%). Plasma elimination half life: 4-5.5 hr; as modified-release preparation : 10-13 hr.

Tamsulosin, an alpha blocker, is used by men to relieve symptoms of BPHsuch as difficulty in beginning the flow of urine, weak stream, and the need to urinate often or urgently (including during the middle of the night). It works by relaxing the smooth muscles in the prostate. Do not use this medication to treat high blood pressure. It can also help your body “pass,” or get rid of, kidney stonesthrough urination. It has also been used to help treat bladder problems in women.

How to use tamsulosin

Read the Patient Information Leaflet if available from your pharmacist before you start taking this medication and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take this medication by mouth as directed by your doctor, usually once daily, 30 minutes after the same meal each day. Swallow this medication whole. Do not crush, chew, or open the capsules.

The dosage is based on your medical condition and response to treatment.

Tamsulosin may cause a sudden drop in your blood pressure, which could lead todizziness or fainting. This risk is higher when you first start taking this drug, after your doctor increases your dose, or if you restart treatment after you stop taking it. During these times, avoid situations where you may be injured if you faint.

Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

If you have not taken this drug for several days, contact your doctor to see if you need to be restarted at a lower dose.

It may take up to 4 weeks before your symptoms improve. Tell your doctor if your condition does not improve or if it worsens.

Not available.

Tell your doctor or pharmacist promptly if any of these effects persist or worsen:

  • dizziness
  • lightheadedness
  • drowsiness
  • runny/stuffy nose
  • ejaculation problems

Tell your doctor right away if you have fainting.

Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.

A very serious allergic reaction to this drug is rare.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.


  • Allergic reaction to this medication
  • Patients with medical history of low blood pressure or certain eye problems (cataracts, glaucoma)
  • This drug may make you dizzy or drowsy.
  • Tell your doctor or dentist if you are taking or have ever taken this medication, and about all the other products you use (including prescription drugs, nonprescription drugs, and herbal products) before having surgery
  • Older adults may be more sensitive to dizziness and low blood pressure
  • This medication should be used only when clearly needed during pregnancy
  • Consult your doctor beforebreast-feeding

Consult your doctor regarding the precautions mentioned above.


Other alpha blocker drugs (such as prazosin, terazosin) may interact with this drug include.

If you are also taking a drug to treat erectile dysfunction-ED or pulmonary hypertension (such as sildenafil, tadalafil), your blood pressure may get too low which can lead to dizziness or fainting.

Other medications may affect how tamsulosin works. Examples include:

  • azole antifungals (such asitraconazole, ketoconazole)
  • boceprevir
  • clarithromycin
  • cobicistat
  • HIV protease inhibitors (such as lopinavir, ritonavir)


If overdose is suspected, contact a poison control center or emergency room immediately. Symptoms of overdose may include: severe dizziness, fainting.


Do not share this medication with others.

Laboratory and/or medical tests (such as prostate exams, blood pressure) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.


Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.


Available Brands

  • Aetams [ Taiwan Biotech ]
  • Alfatam [ Zydus Healthcare Phils ]
  • Harnal D [ Astellas ]
  • Harnal OCAS [ Astellas ]
  • Pimax [ Unicure ]
  • Prozelax [ Biomedis ]
  • Sultam [ Unicure ]
  • Tamsilon [ Kyung Dong Pharm ]
  • Tamsolin [ Getz Pharma ]
  • Tamsul [ Gedeon Richter ]
  • Tamzor [ Cathay Drug ]
  • Urilax [ Littman ]
  • Urolosin [ General ]

Also marketed as

  • Harnal [ Astellas ]

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