Mercaptopurine is a medicine used to treat certain types of cancer and leukaemia.
What are the side effects?
Bone marrow suppression
Temporary effect on liver function
Itchy red rash
Nausea and vomiting
Mouth sores and ulcers
Interactions with other medicines
Giving mercaptopurine at home
- If the liquid gets onto your skin, you must wash the area immediately, using plenty of water. If the skin is sore you should contact your GP (family doctor) for advice.
- If the liquid accidentally gets into your eyes, wash with plenty of running water for at least 10 minutes. If your eyes are sore after this, you should go to your nearest Accident and Emergency (A&E) department.
- If the mixture is spilt on clothing, the spill should be blotted dry with kitchen paper. Clothing should be removed immediately and washed separately from other items. Used kitchen paper should be disposed of as above.
- If you accidentally spill the tablets or liquid on the work surface or floor, wearing gloves, cover the spillage with kitchen paper. Wipe the area with water then clean with household cleaner and water.
- Used paper towels, masks, vomit and dirty disposable nappies should be placed inside two rubbish bags and disposed of along with your normal rubbish.
- Keep all medicines in a safe place where children cannot reach them.
- Mercaptopurine 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 is taking mercaptopurine liquid, it can only be used for eight weeks once opened. Write the date you opened the bottle on the label to remind you.
- 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 necessarily 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 doctor decides to stop treatment with mercaptopurine 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.
- Sometimes, a blood test called TGN is carried out to check whether your child is receiving enough mercaptopurine. You will be advised by the medical team if this is due.
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.