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Glyceryl trinitrate

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

How does it work?

Glyceryl trinitrate (GTN) spray quickly widens your blood vessels, increasing the blood flow to the heart. This helps to reduce chest pain (angina).

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

If you're still having symptoms after using the GTN spray as advised in the action plan CALL 111 IMMEDIATELY.

Step 1: Angina symptoms start 


  • If you're having angina symptoms, stop what you’re doing and rest now.
  • Tell someone how you’re feeling.
  • Take one puff of your GTN spray.

Step 2: Wait five minutes

  • If you still have symptoms after five minutes, take one more puff of your GTN spray.


Step 3: Wait another five minutes

  • If you still have symptoms after another five minutes, treat it as a heart attack. Dial 111 and ask for an ambulance.
  • Chew an aspirin if advised by a paramedic.


If your symptoms go away, you can carry on with your activities gently.

Important: If your angina becomes more frequent, severe, lasts longer or happens when you’re doing very little or resting, see your doctor in the next 24 hours.

What are the side effects?

Sit down before using GTN, as you may experience headaches, flushing or dizziness soon after use.

What else do I need to know?

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.

Tell your health professionals if you’re taking any:

  • supplements
  • natural medicines
  • vitamins
  • alternative therapies.

These can sometimes make your GTN spray less effective.

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

  • sildenafil (Viagra, Avigra, Vedafil, Silvasta)
  • tadalafil (Cialis)
  • vardenafil (Levitra).

Using these medications with GTN spray can cause a drop in blood pressure.

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

GTN spray works immediately to relieve chest pain, however there are some daily-dose medications that reduce the risk of chest pain happening in the first place. These are a range of medications that are used for this, including:

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