NZ Formulary



What does it do?

Doxazosin is used to treat trouble peeing in men caused by an enlarged prostate. It is also used for other conditions such as high blood pressure.

How should you take it?

Take doxazosin regularly as directed with a glass of water.

What if you forget a dose?

Take the missed dose as soon as possible. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with doxazosin including:

  • sildenafil (e.g. Viagra®) or similar medicines

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Chest pain

Prolonged erection (longer than four hours)

Tell your doctor immediately

Headache, dizziness

Change in heartbeat

Short of breath

Tell your doctor

Swollen feet or legs

Tiredness or weakness

Blurred vision

Runny or blocked nose

Stomach upset

Tell your doctor if troublesome

Lightheaded or dizzy after standing up

Stand up slowly. If it continues, or is severe, tell your doctor

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have problems with dizziness, liver or heart problems, or prostate cancer.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Doxazosin can impair your ability to do tasks such as driving or using machines. Alcohol makes this worse. Discuss your risk with your health professional. (search NZTA - Are you safe to drive?)
  • If you are having eye surgery (e.g. cataract operation), tell your doctor that you are taking doxazosin.
  • Do not stop taking doxazosin without talking to your doctor first.