NZ Formulary



What does it do?

Tadalafil is used to treat pulmonary hypertension (high blood pressure in the blood vessels of your lungs), and sometimes other conditions. It improves blood flow by relaxing your blood vessels.

If you are taking tadalafil for erectile dysfunction see separate information sheet "Tadalafil (for erectile dysfunction)".

How should you take it?

Take tadalafil regularly as directed with a glass of water. You can take it with or without food.

What if you forget a dose?

If it is nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take the missed dose as soon as you remember. Do not take two doses at the same time.

Can you take other medicines?

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

  • glyceryl trinitrate (GTN) (e.g. Nitrolingual®, Glytrin®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort) or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Prolonged erection (longer than four hours)

Changes in vision

Tell your doctor immediately

Headache, dizziness


Runny or blocked nose

Muscle aches and pains


Tell your doctor if troublesome

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

Other information:

  • Tell your doctor if you have had a recent stroke, heart or blood pressure problems, or an eye problem called optic neuropathy.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Do not use tadalafil if you are taking a nitrate medicine (e.g. glyceryl trinitrate or isosorbide mononitrate). Taking them both can cause a dangerous drop in blood pressure.
  • Grapefruit, grapefruit juice or sour/Seville oranges may react with tadalafil. Discuss with your pharmacist.
  • Do not stop taking tadalafil without talking to your doctor first.