Tioguanine (6-TG) (Lanvis)

Please read this information in conjunction with our general information on chemotherapy, and with the information in relation to your specific type of cancer.

What is tioguanine ?

Tioguanine is a chemotherapy drug used for the treatment of various types of cancer. It may used as a treatment on its own or in combinatin with other chemotherapy drugs. It is most commonly used to treat leukaemias.

 What does it look like?

It is available in yellow 40mg tablets.

How is it given?

It is given in tablet form which should be swallowed whole.

Side effects

The side effects mentioned below may not affect everyone, as each patient´s reaction to chemotherapy is different. It will also depend on how many chemotherapy drugs you are receiving. If you experience any side effects that you think are related to your chemotherapy, please discuss them with your oncology doctor or chemotherapy nurse.


You will be more prone to infection as tioguanine affects your white cell production from the bone marrow. This effect usually occurs about 10-14 days after your chemotherapy. You will have blood tests to check your levels before every chemotherapy dose to ensure your blood levels have returned to normal. Occasionally your treatment may be delayed until your blood levels come back to normal. If you notice any signs of infection visit your doctor for assessment.
You should contact your doctor or the Oncology Unit straight away if you if you have a sore throat,cough, pain passing urine, redness and swelling at e.g. at a catheter site. Or have a temperature of 38 degrees° C or greater.


Tioguanine can also affect the production of platelets, which can cause bleeding or bruising. Inform your doctor if you notice any unexplained bleeding or bruising.


You may feel lethargic and breathless due to a reduction in your red cells caused by tioguanine. Inform your doctor if you are feeling these effects.

Liver changes

Tioguanine can affect your liver, you will have regular blood tests taken to monitor your liver function. Your liver will return to normal once the treatment is finished.


You may feel very tired. This can last for a few months after your treatment. Inform your doctor or nurse of how you are feeling.

Less common side-effects

Nausea and vomiting

Tioguanine   can make you feel sick nausea   or to to be sick vomit  . It may occur a few hours after you receive your first dose of treatment and can last for a number of days. Your doctor will prescribe some medications to prevent this anti-emetics  .If you continue to feel sick it is important to inform your doctor.


If diarrhoea occurs it can be easily controlled with medicine. It is important to drink plenty of fluid if you experience diarrhoea and to inform your doctor or nurse.

Sore mouth

You may develop a sore mouth or ulcers due to your chemotherapy. You will be prescribed some mouthwashes. Inform your doctor or nurse if your mouth becomes sore or you develop ulcers. You may also experience some taste changes, which will resolve after you finish your treatment.

Additional information


It is important to discuss this with your doctor as your fertility may be affected by tioguanine.


It is important to use a reliable form of contraception while you are on treatment and for at least two years after your treatment has completed. It is not advised to get pregnant or father a child while on treatment as the drugs may affect the foetus.

Other medications

It is important to inform your doctor of any medications that you are taking, including over the counter medications or herbal drugs as they can interfere with some chemotherapy drugs.

Care of chemotherapy tablets

  • Do not handle the tablets, take them directly from the package or use gloves.
  • Take the tablets as prescribed by your doctor.
  • If you miss a dose, inform your doctor.
  • If you vomit immediately after taking a tablet, inform your nurse or doctor, you may need to repeat the dose.
  • Keep them in a cool dry place away from sunlight and out of reach of children.
  • Return any unused tablets to the pharmacy.


  • The Chemotherapy Source Book (2nd edition). M. Perry, Lippincott, Williams and Wilkins, 1997.
  • British National Formulary (53rd edition). British Medical Association and Royal Pharmaceutical Society of Great Britain, March 2007.
  • Cancer Chemotherapy Handbook. T. Dorr and W.L. Fritz, Kimpton Medical Publications, London, 1980.
  • Handbook of Chemotherapy in Clinical Oncology (2nd edition). E. Cvitkovic, J.P. Droz, J.P. Armand and S. Khoury, Scientific Communication International Ltd, 1993.

  • British National Formulary (53rd edition). British Medical Association and Royal Pharmaceutical Society of Great Britain, March 2007.
  • The Cytotoxics Handbook (3rd edition). M. Allwood, A. Stanley and P. Wright, Radcliffe Medical Press, Oxford and New York, 1997.
  • Cancer Chemotherapy Handbook. T. Dorr and W.L. Fritz, Kimpton Medical Publications, London, 1980.

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