Sounds like 'tam-SOO-loe-sin'

Key points about tamsulosin

  • Tamsulosin is used to treat symptoms of urination (peeing) difficulty in men who have an enlarged prostate.
  • Tamsulosin works by relaxing the muscles in the prostate and part of the bladder. It does not make the prostate smaller.
  • It is part of the group of medicines called alpha-blockers.
  • Find out how to take it safely and possible side effects.
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Tamsulosin is used to treat symptoms of difficulty peeing which can happen when you have an enlarged prostate. It can help with difficulty in beginning the flow of urine, weak urine flow, and the need to urinate frequently or urgently – including during the middle of the night.

Read more about enlarged prostate and bladder control problems.

Tamsulosin works by relaxing the muscles in the prostate and part of the bladder. It does not make the prostate smaller. 

In Aotearoa New Zealand tamsulosin is available as 400 microgram capsules.

  • The dose of tamsulosin is 1 capsule once a day.  
  • Always take your tamsulosin exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much tamsulosin to take, how often to take it, and any special instructions.

  • Timing
    • Take tamsulosin capsules with a glass of water (200-250 mLs) at the same time each day.
    • You can take it with or without food.
    • Swallow the capsule whole.
    • Tamsulosin can make your feel dizzy, weak or light headed, so you may prefer to take your dose at bedtime – see dizziness and fainting below. 
  • Missed dose: If you forget your dose, take it as soon as you remember that day. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.

Here are some things to know when you're taking tamsulosin. Other things may be important as well, so ask your healthcare provider what you should know about.

  • Other medicines: Tamsulosin can interact with some medications, herbal supplements and rongoā Māori, so check with your doctor or pharmacist before starting any new products.
  • If you are having eye surgery (eg, a cataract operation), tell your doctor that you are taking tamsulosin.
  • Alcohol: Limit drinking alcohol while you are taking tamsulosin. Alcohol can increase the chance of side effects such as feeling dizzy or faint, be careful when moving from a sitting or lying position, to standing.
  • Driving: Be careful when driving or using tools until you know how this medicine affects you.


Like all medicines, tamsulosin can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.

Dizziness and fainting

Your first dose of tamsulosin may make you feel faint, dizzy or light-headed for a few hours after taking it. To minimise the impact of this effect:

  • Take this dose at bedtime.
  • Be careful when moving from a sitting or lying position, as you are at risk of falls.
  • Stand up slowly from a sitting or lying position.
  • If you feel dizzy or faint, remain lying down until these symptoms have gone.
  • Do not drive or use tools or machines until you know how this medicine affects you.

Other side effects

Side effects What should I do?
  • Headache
  • Try paracetamol. Check that this can be taken with any other medicines you may take.
  • Tell your doctor if this bothers you.
  • Dry mouth
  • Swollen feet or ankles
  • When you sit down, rest your legs on a low stool.
  • Tell your doctor if this bothers you.

  • Changes in your heart beat (a pounding or racing feeling)
  • Chest pain 
  • Tell your doctor immediately or ring Healthline 0800 611 116 .
For more information on side effects, see the Medsafe consumer information leaflet Tamsulosin.(external link)

Did you know that you can report a medicine side effect to the Centre for Adverse Reactions Monitoring (CARM)? Report a side effect to a product(external link).

The following links provide further information on tamsulosin. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Tamsulosin(external link) NZ Formulary 
Tamsulosin(external link) Medsafe Consumer Information, NZ
Tamsulosin(external link) Patient Info, UK


5 questions to ask about your medications(external link) Health Quality and Safety Commission, NZ, 2019 English(external link), te reo Māori(external link)


Tamsulosin(external link) NZ Formulary 
Alpha-blockers(external link) NZ Formulary 
Tamsulosin(external link) Medsafe, NZ

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Maya Patel, Pharmacist

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