GTN is applied under the tongue to allow the drug to be absorbed into the bloodstream.
Once in the bloodstream, the active ingredient (glyceryl trinitrate) opens up many of the body's veins and arteries. This allows the blood to flow faster and more freely, so the heart does not have to work as hard to keep the blood flowing.

What is GTN for?

GTN is for the relief and prevention of angina attacks. Angina can cause you to experience pain, tightness, pressure or discomfort in your chest, arms or neck, particularly when you exert yourself.
You can also use GTN to prevent an attack. For example, if you know that climbing stairs has caused an attack in the past, you could use your GTN before you start.

• If you take alcohol at the same time as using your GTN some of the side effects may be worse than usual.
• GTN is unlikely to affect your ability to drive or operate machinery, but if you feel faint or unwell after using your GTN you should not drive or operate machinery until you feel better.

Instructions on how to use a GTN spray

1. Use your GTN spray to treat an angina attack and before doing any activity that you know might trigger an attack.
2. The usual dose is 1-2 sprays, no more than 3, at any one time. Also check the expiry date, the spray lasts until this time, compared with the tablets.
3. If possible before using the spray, find somewhere to sit down.
4. Take off the plastic cap and hold the spray bottle upright.
5. Hold your breath for a moment to avoid breathing in the spray, then open you mouth and spray the dose under the tongue by pressing down on the pump button then letting go. Then immediately close your mouth and breath normally again.
6. Use one or two sprays at 5 minute intervals (never more then three), until the pain has gone.
7. If the pain has not gone after three sprays, or is worse than usual, or is accompanied by nausea, sweating, faintness, shortness of breath, palpitations then phone your GP straight away, dial 999 for an ambulance or attend the nearest casualty department.

DO NOT DELAY – NIGHT OR DAY

Using you GTN spray for the first time.

1. Check that the pump is working by pressing the pump button a few times until you see a fine mist of liquid.
2. Practice aiming the spray onto something like a tissue so that you can become confident about aiming it correctly when you come to use it during an attack. If you do not need to use the spray very often, remember to check the pump regularly to see it still works properly.

Instructions for GTN tablets

1. GTN tablets must be placed under the tongue and then allowed to dissolve. This is what “sublingual” means. Do not chew or swallow the tablets or they will not work. Preferably you should be sitting down when using the tablets.
2. If one GTN tablet does not relieve your anginal symptoms you may use another, if your symptoms are not improving after three or four tablets or the pain is worse then seek medical advice ( as in the spray directions )
3. If your anginal symptoms are relieved before all the tablet has been dissolved then you may discard the remnant into a tissue and throw it away safely. If any headache persists then this may be responsive to paracetamol.
4. Should you find yourself using an increased number of pills over a given period of time then it would be wise to discuss this with your GP.

DO NOT DELAY – NIGHT OR DAY

Care of GTN tablets

1. GTN tablets must always be kept in a special container which protects them from the light otherwise they will go off.
2. Because GTN tablets go off quickly, and therefore lose their efficiency, once the bottle is opened, you should discard any tablets after 8 weeks of opening the bottle. Ensure that you have obtained a fresh bottle before you discard your old ones. Dispose of medicines safely and if in doubt return them to your pharmacy.

After using GTN

The following side effects are fairly common, around 30-40% of people using GTN experience them at one time or another:

• Taste disturbance (metallic taste)
• Headache
• Flushing (reddening of the face)
• Low blood pressure - this can make you faint, or feel faint, particularly when standing up or getting out of bed.
• Slight slowing down or speeding up of heartbeat (palpitations).

These effects are usually mild and only last a few minutes. If they are prolonged or more severe than usual then contact your doctor immediately otherwise discuss them with your pharmacist or doctor at your next consultation.

Important points to remember

• Keep your spray or tablets with you at all times.
• If you feel an attack coming on, keep calm, inform anyone who is with you and try to find somewhere to sit down.
• USE OF VIAGRA WITH GTN IS ABSOLUTELY CONTRA-INDICATED

See Also

• Stalbridge Surgery | Medical Advice | Heart | Angina

Useful Websites

• Stalbridge Surgery has prepared a list of useful websites for patients
• Online Medical Dictionary compiled by The CancerWEB Project.

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