Glyceryl Trinitrate

What it is for

Glyceryl trinitrate works by opening up arteries, increasing the supply of blood to the heart and so relieving angina pain. It belongs to a group of drugs called 'nitrates'.

Taking glyceryl trinitrate

Use this whenever you have an angina attack or before any activity or stressful situation that you think could cause angina.

Glyceryl trinitrate comes in three forms – tablets, spray and buccal glyceryl trinitrate (suscard buccal).

• Tablets which you place under your tongue and leave to dissolve. Your doctor will tell you how many to take for each attack. The dose is usually one or two tablets, which can be repeated every five minutes until the pain is relieved. Once the pain is relieved, remove the remains of the tablet.
• Spray which you squirt under your tongue when you have an angina attack. Holding the canister upright, have one or two squirts under the tongue. If the pain is not relieved, you can repeat this up to three times, waiting at least five minutes between each use. If your pain has not been relieved after three doses, dial 999 for an ambulance.
• Buccal glyceryl trinitrate (suscard buccal) tablets which you place between your upper lip and gum, where it sticks and slowly dissolves. This is occasionally used to provide relief from angina pain, but may also be used regularly instead of other drugs to help prevent angina.

Further information

• Carry your glyceryl trinitrate with you at all times. Keep it in your handbag or coat pocket, not close to your body.
• Always keep tablets in their original container. When you need to take a tablet, tip the tablets into the lid of the bottle instead of handling them.
• Glyceryl trinitrate tablets cannot be used past eight weeks after opening the bottle for the first time. If any tablets are left after eight weeks, get return them to the pharmacy (chemist) and get a fresh supply from your GP. Glyceryl trinitrate spray can be used after eight weeks, so you can use the spray until the canister is empty, or it reaches the expiry date shown on the canister.
• Glyceryl trinitrate tablets usually tingle or burn when you put them under your tongue. If this does not happen, get a fresh supply.
• Contact your GP if you are having to use your glyceryl trinitrate frequently to relieve your angina.
• You can buy glyceryl trinitrate over the counter from chemists.

Possible side effects

Dizziness, headache and flushed cheeks. These effects should pass after the first few doses. Sit or lie down until the effects pass. You can take paracetamol to relieve your headache. You can reduce these side effects by spitting out the tablet once your pain is relieved.