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Granisetron for nausea and vomiting

Kytril, Sancuso

Granisetron is an anti-sickness medicine for adults.

It is available as tablets to take by mouth, as a patch to be applied to the skin, and as an injection.

The most common side-effects are constipation and headache.

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About granisetron

Type of medicine

An anti-sickness medicine (antiemetic) - a serotonin (5HT3) receptor antagonist

Used for

Prevention or treatment of nausea and vomiting associated with chemotherapy, radiotherapy or surgery (for adults)

Also called

Kytril®; Sancuso®

Available as

Tablets, patches and injection

Granisetron is an anti-sickness medicine, also known as an antiemetic. It is a serotonin receptor antagonist. It is prescribed to stop you from feeling sick (nauseated). It works by blocking the effect of a naturally produced chemical in your body, called serotonin. Serotonin is also referred to as 5HT3.

Chemotherapy, radiotherapy and surgery can all cause the release of an increased amount of serotonin in your body. There are tiny areas in your small intestine and brain, called 5HT3 receptors. Serotonin acts on these receptors and causes you to feel sick. Granisetron works by blocking serotonin from acting on the receptors, and this stops you from feeling sick or being sick (vomiting).

Before taking granisetron

Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking granisetron it is important that your doctor knows:

  • If you are pregnant or breastfeeding.

  • If you have been told you have an irregular heartbeat.

  • If you have any problems with the way your liver works.

  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.

  • If you have ever had an allergic reaction to a medicine.

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How to take granisetron

  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about granisetron, and it will also provide you with a full list of the side-effects which you could experience from taking it.

  • If you are being prescribed granisetron because you are due to have surgery, you will be given an injection of granisetron shortly before the operation. You could be given further doses by injection after the surgery if it is needed. A doctor or nurse will administer the injections to you.

  • If you are due to have a chemotherapy or radiotherapy treatment that could cause you to feel sick, your doctor will prescribe granisetron for you to have before the treatment:

    • If you are able to take tablets, you will be given one dose of tablets to take within the hour before your treatment. You will then be asked to continue to take granisetron tablets for a few days - it is usual to be prescribed 2 mg daily (as one or two doses) for up to seven days. Swallow the tablets whole with a drink of water. You can take granisetron either with or without food.

    • If you are not able to take tablets, you could be given a skin patch containing granisetron. The patch will be applied to your upper arm, or possibly your tummy (abdomen), 24-48 hours before your treatment is due to begin. Leave it in place during your treatment and for a further 24 hours after the treatment has finished before you remove it. You can wash and bathe as normal while you are wearing the patch, but you should not allow the patch to be in direct contact with bright sunlight or heat (such as an electric blanket or a hot water bottle). Even after you have removed the patch, the area where the patch was should be protected from bright sunlight for a further 10 days. When you remove the patch, fold it in half with the sticky sides together, and ask your pharmacist or clinic to dispose of it.

    • Granisetron can also be given by injection. If this is the treatment prescribed for you, a doctor or nurse will administer the injections to you.

Getting the most from your treatment

  • Even if you do not feel like eating or drinking, try to sip water regularly to prevent you from becoming lacking in fluids (dehydrated). Also, rather than trying to eat three main meals a day, try eating small, simple but nourishing snacks, every few hours.

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Can granisetron cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the more common ones associated with granisetron. The best place to find a full list of the side-effects which can be associated with your medicine, is from the manufacturer's printed information leaflet supplied with the medicine. Alternatively, you can find an example of a manufacturer's information leaflet in the reference section below. Speak with your doctor or pharmacist if any of the following continue or become troublesome.

Very common

granisetron side-effects (these affect more than 1 in 10 people)

What can I do if I experience this?


Try to eat a well-balanced diet, and drink several glasses of water each day. Let your doctor know if this continues


Drink plenty of water and ask your doctor to prescribe a suitable painkiller


granisetron side-effects

(these affect fewer than 1 in 10 people)

What can I do if I experience this?

Sleeping problems

This should soon pass


Drink plenty of water, and if troublesome, speak with your doctor

Changes to some blood tests

Your doctor will monitor for this

Important: in a very few people, medicines like granisetron can cause a problem called serotonin syndrome. Although this occurs only rarely, should you develop stiff or shaky muscles, a very high temperature (fever), a fast heartbeat, or become confused or agitated, you should call for medical assistance straightaway.

If you experience any other symptoms which you think may be due to the medicine, speak with your doctor or pharmacist for further advice.

How to store granisetron

  • Keep all medicines out of the reach and sight of children.

  • Store in a cool, dry place, away from direct heat and light.

Important information about all medicines

Important information about all medicines

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

If you are having an operation or any dental treatment, tell the person carrying out the treatment which medicines you are taking.

If you buy any medicines, check with a pharmacist that they are suitable to take with your other medicines.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

Report side effects to a medicine or vaccine

If you experience side effects, you can report them online through the Yellow Card website.

Further reading and references

Article history

The information on this page is written and peer reviewed by qualified clinicians.

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