Tioguanine

Tioguanine is a medicine used at Great Ormond Street Hospital (GOSH) to treat certain types of cancer and leukaemia.

How is tioguanine given?

For the treatment of leukaemia, tioguanine is given by mouth in tablet or liquid form once a day. It should be taken one hour after food in the evening but not with milk products as these affect how the medicine is absorbed. For other types of cancer, tioguanine should be taken as directed by your doctor, nurse or pharmacist.

What are the side effects of tioguanine?

Bone marrow suppression

There will be a temporary reduction in how well your child’s bone marrow works. This means your child may become anaemic, bruise or bleed more easily than usual, and have a higher risk of infection. Your child’s blood counts will be checked regularly to see how the bone marrow is working. Please tell your doctor if your child seems unusually tired, has bruising or bleeding, or any signs of infection, especially a high temperature. 

Diarrhoea

Please tell the doctor or nurse if your child has diarrhoea that is not controlled or persists. It is important that your child drinks plenty of fluids.

Nausea and vomiting

Anti-sickness medicines can be given to reduce or prevent these symptoms. Please tell your doctor or nurse if your child’s sickness is not controlled or persists.

Temporary effect on liver function

Some children are sensitive to tioguanine, which can cause changes in liver function. This should return to normal when the treatment is finished. If your child’s liver function is temporarily serious affected then the treatment will be changed. Blood tests may be taken to monitor your child’s liver function (LFTs). Please contact your doctor immediately if your child complains of pain in his or her right side or develops a yellow skin tinge.

Tioguanine and interactions with other medicines

Some medicines can react with tioguanine, altering how well it works. Always check with your doctor or pharmacist before giving your child any other medicine, including medicines on prescription from your family doctor (GP), medicines bought from a pharmacy (chemist) or any herbal or complementary medicines.

Important information you should know about tioguanine

  • Keep all medicines in a safe place where children cannot reach them.
  • Tioguanine tablets or liquid should be kept in a cool, dry place away from direct sunlight or heat.
  • You should handle these medicines with care, avoiding touching them where possible. If you are pregnant or think you could be pregnant, please discuss handling instructions with your doctor, nurse or pharmacist. Please see our special handling requirements information sheet for further details.
  • If your child vomits after taking the dose, inform the doctor or nurse. Do not give them another dose.
  • If you forget to give your child their dose, do not give them a double dose. Inform your doctor or nurse and keep to your child’s regular dose schedule.
  • Sometimes it is necessary to halve tablets to get the correct dose. A tablet cutter may be used for this but you should keep it only for cutting chemotherapy tablets.
  • If your child cannot swallow tablets, you can ask the pharmacist for the liquid preparation.
  • Vomit and dirty disposable nappies should be placed inside two rubbish bags and disposed of along with your normal rubbish.
  • If your doctor decides to stop treatment with tioguanine or the medicine passes its expiry date, return any remaining medicine to the pharmacist. Do not flush it down the toilet or throw it away.
Compiled by: 
The Pharmacy department in collaboration with the Child and Family Information Group
Last review date: 
November 2014
Ref: 
2014F0668

Disclaimer

Please read this information sheet from GOSH alongside the patient information leaflet (PIL) provided by the manufacturer. If you do not have a copy of the manufacturer’s patient information leaflet please talk to your pharmacist. A few products do not have a marketing authorisation (licence) as a medicine and therefore there is no PIL.

For children in particular, there may be conflicts of information between the manufacturer’s patient information leaflet (PIL) and guidance provided by GOSH and other healthcare providers. For example, some manufacturers may recommend, in the patient information leaflet, that a medicine is not given to children aged under 12 years. In most cases, this is because the manufacturer will recruit adults to clinical trials in the first instance and therefore the initial marketing authorisation (licence) only covers adults and older children.  

For new medicines, the manufacturer then has to recruit children and newborns into trials (unless the medicine is not going to be used in children and newborns) and subsequently amend the PIL with the approved information. Older medicines may have been used effectively for many years in children without problems but the manufacturer has not been required to collect data and amend the licence. This does not mean that it is unsafe for children and young people to be prescribed such a medicine ‘off-licence/off-label’. However, if you are concerned about any conflicts of information, please discuss with your doctor, nurse or pharmacist.