Tioguanine

Tioguanine is a chemotherapy drug used to treat acute myeloid leukaemia (AML), acute lymphoblastic leukaemia (ALL) and chronic myeloid leukaemia (CML). It may also be used to treat other cancers.

It is best to read this information with our general information about chemotherapy and the type of cancer you have.

Tioguanine is given as tablets. You usually have it as an outpatient. Your cancer doctor, nurse, or pharmacist will tell you how often you will have it.

Like all chemotherapy drugs, tioguanine can cause side effects. Some of the side effects can be serious, so it is important to read the detailed information below.

Your healthcare team can give you advice on how to manage any side effects. Tell your doctor or nurse straight away if you:

  • have a temperature
  • feel unwell
  • have severe side effects, including any we do not mention here.

Rarely, side effects may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

If you need medical attention for any reason other than cancer, always tell the healthcare staff that you are having this treatment.

What is tioguanine?

Chemotherapy

This video provides a brief overview of chemotherapy treatment, how it can be given, how it works and possible side effects.

About our cancer information videos

Chemotherapy

This video provides a brief overview of chemotherapy treatment, how it can be given, how it works and possible side effects.

About our cancer information videos


How tioguanine is given

During treatment you usually see a cancer doctor, a chemotherapy nurse or a specialist nurse, and a specialist pharmacist. This is who we mean when we mention doctor, nurse, or pharmacist in this information.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level for you to have chemotherapy.

You will see a doctor or nurse before you have chemotherapy. They will ask you how you have been feeling. If your blood results are okay, the pharmacist will prepare your chemotherapy. Your nurse will tell you when your treatment is likely to be ready.

Your course of chemotherapy

Tioguanine comes in tablets, so you can take it at home. It may be given on its own, or with other chemotherapy drugs.

Chemotherapy is usually given as a course of several cycles of treatment over a few months. Your nurse or doctor will discuss your treatment plan with you.

The nurse or pharmacist will give you the tablets to take home. Always take them exactly as explained. This is important to make sure they work as well as possible for you. You may be given tablets of different strengths.

Your nurse or pharmacist may also give you anti-sickness (anti-emetic) drugs and other medicines to take home. Take all your tablets exactly as they have been explained to you.

Taking tioguanine tablets

The tablets must be swallowed whole with a glass of water. They should not be chewed or crushed. If you need to break your tablet in half to help with swallowing, do not inhale any tablet powder. It is important to wash your hands afterwards.

Take them at the same time every day.

If you forget to take the tablets, let your doctor or nurse know. Do not take a double dose.

Other things to remember about your tablets:

  • Keep them in the original package and at room temperature, away from heat and direct sunlight.
  • Keep them safe and out of sight and reach of children.
  • If you are sick after taking the tablets, contact the hospital. Do not take another dose.
  • If your treatment is stopped, return any unused tablets to the pharmacist.


About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects.

You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we haven’t listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.


Common side effects of tioguanine

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shivery
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine often.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. Tell your doctor if you have any bruising or bleeding that you cannot explain. This includes:

  • nosebleeds
  • bleeding gums
  • tiny red or purple spots on the skin that may look like a rash.

Some people may need a drip to give them extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Feeling sick

You may feel sick during chemotherapy. Your doctor will give you anti-sickness drugs to help prevent or control sickness. Take the drugs exactly as your nurse or pharmacist tells you. It is easier to prevent sickness than to treat it after it has started.

If you feel sick, take small sips of fluids and eat small amounts often. If you continue to feel sick, or if you vomit more than once in 24 hours, contact the hospital as soon as possible. They will give you advice and may change the anti-sickness drug to one that works better for you.

Diarrhoea

If you have diarrhoea, contact the hospital for advice. Try to drink at least 2 litres (3½ pints) of fluids every day. It can help to avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Sore mouth

You may get a sore mouth or mouth ulcers. This can make you more likely to get a mouth infection. Use a soft toothbrush to clean your teeth or dentures in the morning, at night and after meals.

If your mouth is sore:

  • tell your nurse or doctor – they can give you a mouthwash or medicines to help
  • try to drink plenty of fluids
  • avoid alcohol, tobacco, and foods that irritate your mouth.

Feeling tired

Feeling tired is a common side effect. It is often worse towards the end of treatment and for some weeks after it has finished. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.

Liver changes

Tioguanine can cause changes in the way your liver works. These will usually go back to normal after treatment finishes. You will have regular blood tests to check how well your liver is working.

Tioguanine may cause the skin and whites of your eyes to become yellow (jaundice). Tell your nurse or doctor straight away if you notice this.

It’s also important to let them know if you get pain in your liver area (the upper right-hand side of the tummy) or swelling in your feet or legs. These may mean there are changes in how the liver is working.

A photo of Stuart talking about neutropenic sepsis

Neutropenic sepsis

Stuart talks about he how coped with neutropenic sepsis, an infection which can be a side effect of chemotherapy.

About our cancer information videos

Neutropenic sepsis

Stuart talks about he how coped with neutropenic sepsis, an infection which can be a side effect of chemotherapy.

About our cancer information videos

Coping with fatigue

Denton describes how he coped with fatigue (tiredness) during his treatment for prostate cancer.

About our cancer information videos

Coping with fatigue

Denton describes how he coped with fatigue (tiredness) during his treatment for prostate cancer.

About our cancer information videos


Less common side effects of tioguanine

Raised levels of uric acid in the blood

This treatment may cause the cancer or leukaemia cells to break down quickly. This releases uric acid (a waste product) into the blood. The kidneys usually get rid of uric acid but may not be able cope with large amounts. Too much uric acid can cause swelling and pain in the joints, which is called gout.

Your doctor may give you tablets called allopurinol (Zyloric®) to help prevent this. Drinking at least 2 litres of fluid a day will also help. You will have regular blood tests to check the uric acid levels.

Severe tummy pain

Very rarely, tioguanine may cause a serious problem with your bowels.

Contact your doctor straight away if you have any of these symptoms:

  • severe tummy pain
  • feeling sick
  • being sick
  • diarrhoea
  • a high temperature.


Other information about tioguanine

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Symptoms of a blood clot include:

  • pain, redness or swelling in a leg or arm
  • breathlessness
  • chest pain. 

If you have any of these symptoms, contact a doctor straight away. 

A blood clot is serious, but can be treated with drugs that thin the blood. Your doctor or nurse can give you more information.

Other medicines

Some medicines can affect chemotherapy or be harmful when you are having it. This includes medicines you can buy in a shop or chemist. Tell your cancer doctor about any drugs you are taking, including vitamins, herbal drugs and complementary therapies.

Alcohol

Your doctor may advise you not to drink alcohol while you're taking tioguanine.

Fertility

Some chemotherapy drugs can affect whether you can get pregnant or father a child.

If you are a woman, your periods may become irregular or stop. This may be temporary, but for some women it is permanent. Your menopause may start sooner than it would have done.

There may be ways to preserve fertility for men and women. If you are worried about fertility, it is important to talk with your doctor before you start chemotherapy treatment.

Contraception

Your doctor will advise you not to get pregnant or father a child while having this treatment. The drugs may harm the developing baby. It is important to use effective contraception during your treatment.

Breastfeeding

Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.

Sex

If you have sex during this course of chemotherapy, you need to use a condom. This is to protect your partner in case there is any chemotherapy in semen or vaginal fluids.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses that you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.