Glyceryl trinitrate rectal ointment

  • Use the ointment twice daily for up to eight weeks.
  • The most common side-effect is headache.

About glyceryl trinitrate rectal ointment

Type of medicine Nitrate
Used for Pain relief in anal fissures
Also called Rectogesic®
Available as Rectal ointment

An anal fissure is a small tear of the skin around your back passage (anus). Glyceryl trinitrate (GTN) rectal ointment works by relaxing the muscle just inside your back passage. Relaxing this muscle increases the flow of blood to the area, which promotes the healing process and eases pain. It can be helpful where other treatments have not been effective.

Before using glyceryl trinitrate rectal ointment

To make sure this is the right treatment for you, before you start using this ointment it is important that your doctor or pharmacist knows:

  • If you are pregnant, trying for a baby or breast-feeding.
  • If you have heart disease, or any problems with your liver or kidneys.
  • If you have low blood pressure.
  • If you have migraines or severe headaches.
  • If you have been told by a doctor you have anaemia (low levels of iron in your blood) or hypoxaemia (low levels of oxygen in your blood).
  • If you have an underactive thyroid.
  • If you have glaucoma (an increased pressure in your eye).
  • If you have recently had a head injury.
  • If you have ever had an allergic reaction to a medicine.
  • If you are taking other medicines, including those available to buy without a prescription, herbal or complementary medicines. It is particularly important that you tell your doctor if you are using any products to help treat erectile dysfunction (such as Viagra®).

How to use glyceryl trinitrate rectal ointment

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about the ointment and a full list of side-effects which you may experience from using it.
  • There is a measuring line on the outside of the carton for you to measure 2.5 cm of ointment. Squeeze 2.5 cm of the ointment out of the tube on to your finger. If you prefer, you can use a finger covering such as a finger cot (available from pharmacies) or a disposable glove. Then, using your finger, gently insert the ointment just inside your back passage. Use the ointment this way every 12 hours until the pain goes away. You can use the ointment for up to eight weeks if needed.

Getting the most from your treatment

  • Remember to follow any lifestyle or dietary advice you have been given by your doctor. Try to avoid becoming constipated, by eating a high-fibre diet and drinking several glasses of water each day.
  • It is best not to drink alcohol while you are using GTN rectal ointment. Alcohol will increase the chance that you experience side-effects such as feeling dizzy or light-headed.
  • If you experience any bleeding from your back passage, or if your symptoms do not improve, you should discuss this with your doctor.
  • If you buy any medicines, check with a pharmacist that they are suitable for you to take while you are using GTN rectal ointment.

Can glyceryl trinitrate rectal ointment cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common glyceryl trinitrate side-effects
What can I do if I experience this?
Headache Ask your pharmacist to recommend a suitable painkiller.
If the headache is severe or if it continues,
ask your doctor for further advice
Feeling light-headed, dizzy or tired Get up slowly until you know how you react
Blurred vision Take care if you drive or use tools or machines
Diarrhoea, local burning or itching, rectal bleeding, feeling sick If any of these become troublesome, speak with your doctor

If you experience any other symptoms which you think may be due to this ointment, speak with your doctor or pharmacist.

How to store glyceryl trinitrate rectal ointment

  • Do not store or use the ointment for longer than eight weeks once it has been opened.
  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.