Glyceryl trinitrate (spray)

Commonly called GTN spray

Easy-to-read medicine information about glyceryl trinitrate spray – what it is, how to use it safely and possible side effects. Glyceryl trinitrate spray is commonly called GTN spray.

Type of medicine Also called
  • Belongs to a group of medicines called nitrates
  • Used to treat chest pain (angina)
  • Glytrin®
  • Nitrolingual®
  • GTN spray

What is GTN spray?

GTN spray is used to relieve angina. Angina is chest pain which may spread to your throat, jaw, neck, shoulders or arms. Angina happens when the blood supply to the muscles of your heart are restricted, due to narrowing of the blood vessels supplying your heart.

GTN spray works by widening blood vessels, letting more blood and oxygen reach your heart. This reduces strain on your heart, making it easier for your heart to pump blood. Read more about angina

GTN spray is sprayed under your tongue so that it starts having an effect immediately. In this way, it provides rapid relief from angina symptoms. It can also be used for when angina pain is expected to happen, such as before exercise that is likely to cause chest pain (eg, before climbing stairs).

In New Zealand, GTN spray is available on prescription from your doctor. You can also buy GTN spray from your pharmacy without a prescription, after consultation with your pharmacist. 

Dose

If you experience chest pain (angina), chest ache or chest discomfort, take these steps:

  1. Stop what you are doing sit down and rest. Use 1 spray under your tongue and wait 5 minutes. If your angina is relieved by rest or your spray, you can resume your activities gently.
  2. If the pain is still present, use 1 more spray and wait 5 minutes.
  3. If the pain is still present, call 111 and ask for an ambulance.   

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To avoid chest pain before doing some activities (like exercise), use 1 spray under your tongue 5–10 minutes before the activity.

How to use GTN spray

  • If possible, sit down when using GTN spray.
  • Remove the cap. Hold the canister upright with your forefinger on top of the white button. There is no need to shake the canister.
  • Open your mouth and bring the spray nozzle as close as possible, aiming it under your tongue.
  • Press the button firmly, directing the spray under your tongue while holding your breath.
  • Keep the button held down until all the dose has been released. Close your mouth immediately but do not inhale the spray.
  • If needed, follow the steps above again.
  • No more than 2 doses are recommended at one time.
  • Always replace the cap after use.
  • You may feel a slight tingling in your mouth when you use GTN spray. This is harmless.

Nitrolingual pump handle

If you have problems using the spray because of difficulty with coordination or with your joints, eg, due to arthritis, you can use a nitrolingual pump handle.

This plastic device is fitted onto the top of the GTN bottle and makes it much easier to squeeze down to release a spray of the medicine during an angina attack. Read more: Nitrolingual pump handle Arthritis NZ

Other handy tips

  • Keep your GTN spray with you at all times: Make sure you always have your GTN spray with you so you know where it is when you need it. Don't hesitate to use it.
  • Keep a spare GTN spray handy: Make sure you get a new one before the old one runs out.
  • Sit down before using GTN spray: It can make you feel light-headed and dizzy.
  • Check the expiry date on the canister: After this date the spray may not work, so you will need to get a new spray.
  • Storage: You can carry the spray in your pocket but it needs to be stored below 25ºC, so don't keep it in your car during summer.

Precautions – before using GTN spray

  • Are you pregnant, planning a pregnancy or breastfeeding?
  • Do you have low blood pressure?
  • Have you recently had a heart attack?
  • Are you are taking or using any other medicines? This includes any medicines you are using that are available to buy from a pharmacy, supermarket or natural health store without a prescription. 

If so, it’s important that you tell your doctor or pharmacist before getting a GTN spray. Sometimes a medicine isn’t suitable for a person with certain conditions or it can only be used with extra care. It is particularly important that you tell your doctor or pharmacist if you are using any medicines to help treat erectile dysfunction.

Do not use GTN spray if you are taking medicines used to treat erection problems, such as:

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

Using erectile dysfunction medicine with GTN spray can cause a sudden decrease in blood pressure, which can be life threatening.

Possible side effects

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

Side effects What should I do?
  • Headache
  • This is quite common when you use GTN spray and should settle after a few days.
  • Tell your doctor if it is ongoing.
  • Dizziness
  • Feeling lightheaded
  • Feeling faint when you stand up
  • This is quite common when you use GTN spray and usually goes away with time.
  • Sit down when using the spray.
  • Avoid alcohol.
  • Tell your doctor if this continues.
  • Changes in your heartbeat (either fast, slow or irregular)
  • Tell your doctor.
  • An allergic reaction such as skin rash, itching, swelling of your lips, face and mouth, or difficulty breathing, such as chest tightness or wheezing
  • Tell your doctor immediately or phone Healthline 0800 611 116.

Interactions

GTN spray can interact with a few medications and herbal supplements so check with your doctor or pharmacist before starting GTN spray or before starting any new medicines. GTN spray interacts with medicines to treat erectile problems such as sildenafil (Viagra, Avigra, Vedafil, Silvasta), tadalafil (Cialis) and vardenafil (Levitra).

Learn more

The following link has more information on GTN spray:

Glyceryl trinitrate (spray) New Zealand Formulary Patient Information

References

  1. Glyceryl trinitrate (systemic) New Zealand Formulary
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 03 Jun 2019