Glyceryl trinitrate (GTN)

Glyceryl trinitrate (GTN) spray can relieve symptoms of angina. Read about how GTN spray works and its possible side effects.

How to get GTN spray

Glyceryl trinitrate (GTN) spray is also called Nitrolingual or Glytrin.

Your doctor may prescribe you GTN spray. You can also buy it from your pharmacy without a prescription, after talking to your pharmacist.

Talk your doctor, nurse or pharmacist about how to use your spray correctly.

How does GTN spray work?

GTN spray relaxes your blood vessels to widen them. This increases blood flow to the heart muscle and helps relieve the symptoms of angina.

If you have angina symptoms, follow the steps in the angina action plan:

Angina action plan infographic showing step‑by‑step instructions to stop, use GTN spray, wait 5 minutes between doses and call 111 if chest pain or angina symptoms persist, Heart Foundation New Zealand.

If your symptoms don’t go away when you take your GTN spray, call 111 immediately.

Your doctor may also give you other medication to reduce the risk of angina symptoms starting. These are pills you take each day, called long-acting nitrates.

Comparison graphic of long-acting nitrates and GTN spray for angina - daily pill icon versus spray icon, Heart Foundation NZ

Other heart medications, such as beta blockers and calcium channel blockers, can also be used to reduce your angina symptoms.

Side effects of GTN spray

Sit down before using GTN spray, as common side effects include:

  • dizziness
  • feeling faint or light-headed when you stand up
  • headache
  • going red in the face (flushing).

Talk to your doctor or call Healthline (0800 611 116) if you notice changes in your heartbeat (fast, slow or irregular).

Talk to your doctor if the side effects are worrying you. Don’t stop taking your medication without talking to your doctor first.

What else do I need to know?

Your doctor may tell you to use GTN spray before activities that can trigger angina, such as exercise, climbing stairs or sex.

Always keep your GTN spray with you and keep a spare one handy.

It’s a good idea to test your spray to make sure it’s working effectively.

Check the expiry date on your GTN spray regularly. Your spray may not work as well after this date, so you’ll need a new one.

GTN spray and other medications

Tell your doctor and pharmacist if you’re taking any:

  • vitamins
  • supplements
  • natural medicines
  • medicines bought from a pharmacy without a prescription
  • alternative therapies.

These can sometimes make your GTN spray less effective or stronger.

Talk to your doctor if you use GTN spray and you’re planning to get pregnant or are breastfeeding.

Do not use GTN spray if you’re taking medicines for difficulties with erections, such as:

  • sildenafil, also called Viagra, Vedafil, Silvasta
  • tadalafil, also called Cialis
  • vardenafil, also called Levitra.

Using these medications with GTN spray can cause a dangerous drop in blood pressure. This can be life-threatening.

Related treatments and conditions

Angina

Search for another heart medication